Shell V-Power

[savage86]

Hi everyone I am in the process of writing an essay on the shell V-Power brand for my Marketing degree. For me to pass I need up to date opinions on what people think of the brand and I thought you guys would be the perfect people to ask being mostly big car and bike fans.

If you could answer just a few questions I would be extremely grateful, put as much or as little detail as you have time for. However if there is a common opinion or problem that you know about Shell V-Power I would like to here it.


1 Have you heard of shell V-power?


2 Do you sometimes/regularly purchase Shell V-power or fuels that give higher performance (if so specify)



3 Do you think Shell V-power would increase the performance of your car?




4 Would you buy Shell V-power if they lowered the price?



5 In a situation where you were forced to buy a high performance fuel brand would you choose Vpower over other products?

The answers dont have to be that formal an open discussion is fine im trying to gather opinions more than anything,

thanks in edvance guys.

[Eki]

Hi everyone I am in the process of writing an essay on the shell V-Power brand for my Marketing degree. For me to pass I need up to date opinions on what people think of the brand and I thought you guys would be the perfect people to ask being mostly big car and bike fans.

If you could answer just a few questions I would be extremely grateful, put as much or as little detail as you have time for. However if there is a common opinion or problem that you know about Shell V-Power I would like to here it.


1 Have you heard of shell V-power?


2 Do you sometimes/regularly purchase Shell V-power or fuels that give higher performance (if so specify)



3 Do you think Shell V-power would increase the performance of your car?




4 Would you buy Shell V-power if they lowered the price?



5 In a situation where you were forced to buy a high performance fuel brand would you choose Vpower over other products?

The answers dont have to be that formal an open discussion is fine im trying to gather opinions more than anything,

thanks in edvance guys.
1. Yes

2. I have tried Shell V-power

3. I might be imagining, but I think my car runs more smoothly with Shell V-power than with 95 octane

4. Could be. Currently it costs about 8 c/litre more than 95 octane, so I don't use it that often

[schmenke]

1 Have you heard of shell V-power?
Yes.

2 Do you sometimes/regularly purchase Shell V-power or fuels that give higher performance (if so specify)
No.

3 Do you think Shell V-power would increase the performance of your car?
No.

4 Would you buy Shell V-power if they lowered the price?
No.

5 In a situation where you were forced to buy a high performance fuel brand would you choose Vpower over other products?
No.

[Rollo]

1 Have you heard of shell V-power?
Of course, Shell has quite an agressive marketing campaign.

2 Do you sometimes/regularly purchase Shell V-power or fuels that give higher performance (if so specify)
Only if I am travelling long distances (500+ miles) and for the reasons of extra fuel density and not performance.

3 Do you think Shell V-power would increase the performance of your car?
I know that it will not.

Octane is NOT a measure of power but of the fuels’ resistance to ignition from heat. A higher-octane fuel, under identical combustion chamber conditions, will burn slower.

This sounds counter-intiuative but in regular compression cars, higher-octane fuel will actually produce less power because the burn rates are slower. Higher octane fuels in high compression engines are more efficient in releasing the potential chemical energy that already exists, but on a per litre basis, the amount of potential energy in 87, 91, 95, 98 or 101 rated fuel is almost exactly the same.

4 Would you buy Shell V-power if they lowered the price?
On a percentage basis, the price would need to fall by about 16% to make it viable to put in my Ka in the long run.

5 In a situation where you were forced to buy a high performance fuel brand would you choose Vpower over other products?
By "forced" I suppose you mean that I am running out of petrol in a remote area and it happens to be the only pump. By definition, there are no other products.

[Zico]

1. yes

2. yes, very occasionally I use V-power and BP ultimate.

3. Over other 98 Ron Fuels No it will not.. over regular 95 Ron Fuel? yes it runs smoother, gives better mpg and surprisingly on a very cold morning I do get a small bhp increase, probably more due to the colder denser air and the temp sensor making the ECU switch to a richer setting.

4. yes I would if it dropped enough to make it worthwhile.

5. It is good but No, I rate BP ultimate just as highly..

[schmenke]

Using a higher octane fuel does squat unless the ECU is reprogrammed accordingly.

[Magnus]

1 Have you heard of shell V-power?
Yes

2 Do you sometimes/regularly purchase Shell V-power or fuels that give higher performance (if so specify)
Once


3 Do you think Shell V-power would increase the performance of your car?
It does do that in every car, allthough on older cars you probably wont notice the diff. The difference in energydensity between 95 octane ron and 98 octane ron is abt 1,5 percent, allthough fuels are under continous development so this varies a little bit from time to time. The diff will however be much greater if you hade adaption and can make use of the diference regarding ignition from high pressure; ie knocksensor plus an ecu which continually varies the advance in order to get as efficient as possible. You will get most out of it on supercharged engines. I doubt the engine will run more smothly though; higher resistance to knock would rather imply a rougher run. Ofcourse it will be harder to spot the diff between the 98 and the V-power. I will not dwell further into differnt combustion chamber layouts, squish, swirls and so on...

4 Would you buy Shell V-power if they lowered the price?
Yes

5 In a situation where you were forced to buy a high performance fuel brand would you choose Vpower over other products?

Yes, because there are not other in Sweden for the moment. But I have octanebooster in my workshop so it´s allright :)

[Zico]

Using a higher octane fuel does squat unless the ECU is reprogrammed accordingly.

My cars runs smoother and I get more mpg... not a massive improvement to justify the extra cost but defo an improvement.

[Daniel]

I agree with Zico. I always use vpower diesel in my car and it runs much more smoothly and goes further on a tank and also smokes less when it smokes. But then again vpower diesel is a bit different to normal diesel.

[Magnus]

The cetaneno is higher on this diesel, which is the main differnce in comparition to normal dieselfuels. the sulphur rates are also lower, but his varies quite a lot between different parts of the world. it also has better foaming characteristics and some extra detergents. According to shell it also prevents cloggong tha nozzles of the injector better then ordinary fuel. This aspect is most important in supercharged engines where clogged injectors can cause overheating in the combustion chamber; the atomization process of the injectors is extremely energy consuming; when the diesel then enters the warm combustionchamber it thus cools it alot.

[Rollo]

My cars runs smoother and I get more mpg... not a massive improvement to justify the extra cost but defo an improvement.

Several things worth noting about this:

1. You're most likely getting better fuel economy because of that little thing known as the Placebo Effect. Because you think you're getting better economy, then you'll be less inclined to use the loud pedal. The only way to actually get you to prove this for yourself is to do a double blind test with someone else who doesn't know what petrol is going into the car.

2. All cars produce more power in cooler air, that's because the air itself is capable of holding more oxygen. Added to this, it's also denser and so the air/fuel mixture will be burnt more efficiently. Practical proof of this happens on the dragway, where the fastest runs are done at the end of the day with cool air, warm tracks and lots of rubber laid down.

3. If your car runs smoother, maybe it's "knocking". True, a higher octane rated fuel will burn more evenly and slower, but the root cause are deposits on the inside of the engine.

[Zico]

Several things worth noting about this:

1. You're most likely getting better fuel economy because of that little thing known as the Placebo Effect. Because you think you're getting better economy, then you'll be less inclined to use the loud pedal. The only way to actually get you to prove this for yourself is to do a double blind test with someone else who doesn't know what petrol is going into the car.

2. All cars produce more power in cooler air, that's because the air itself is capable of holding more oxygen. Added to this, it's also denser and so the air/fuel mixture will be burnt more efficiently. Practical proof of this happens on the dragway, where the fastest runs are done at the end of the day with cool air, warm tracks and lots of rubber laid down.

3. If your car runs smoother, maybe it's "knocking". True, a higher octane rated fuel will burn more evenly and slower, but the root cause are deposits on the inside of the engine.

I agree that are most probably correct with both points 2 and 3... but wouldnt a knocking engine be less fuel efficient?

[Daniel]

I agree that are most probably correct with both points 2 and 3... but wouldnt a knocking engine be less fuel efficient?
Do you not own a fairly high compression engined car Zico? :)

[Zico]

Do you not own a fairly high compression engined car Zico? :)

Engine is the NFX (TU5J4) 1.6, 16 valve in a 106 Gti, Is 10.8:1 considered high?

[Zico]

Quote from Wiki..
"Due to pinging (detonation), the CR in a gasoline/petrol powered engine will usually not be much higher than 10:1,"

Judging from which.. 10.8:1 must be a relatively high ratio for a standard engine. The inclusion of a knock sensor in the TU5J4, which can retard the ignition timing, may well account for this ratio choice.

Does this explain my findings?

[mullenswrc]

1 Have you heard of shell V-power?
Yes.

2 Do you sometimes/regularly purchase Shell V-power or fuels that give higher performance (if so specify)
Regularly. Been told by the previous owner of my rally car to only run it on higher octane fuel. I Run the road car on standard.

3 Do you think Shell V-power would increase the performance of your car?
Mid - low power road cars no but does give slightly better fuel economy. Most other types of vehicles maybe yes.

4 Would you buy Shell V-power if they lowered the price?
Yes.

5. In a situation where you were forced to buy a high performance fuel brand would you choose Vpower over other products?
No. Il put it in if im passing Shell. I tend to go for the Tesco 99, because Vpower is 98 octane I believe.

[Dave B]

1 Have you heard of shell V-power?
Yes, it's been well advertised.

2 Do you sometimes/regularly purchase Shell V-power or fuels that give higher performance (if so specify)
No.


3 Do you think Shell V-power would increase the performance of your car?
No



4 Would you buy Shell V-power if they lowered the price?
Only if it were no more expensive than "regular" unleaded and offered some genuine benefit.


5 In a situation where you were forced to buy a high performance fuel brand would you choose Vpower over other products?
No, but nor would I reject it. I'd buy my petrol, as now, from whichever retailer I happen to be closest to when I need fuel.

[Daniel]

From what I've seen in most tests the Tesco 99 fuel has been shown to be the best widely available pump fuel. BP Ultimate 102 is the best pump fuel money can buy but it's not exactly widely available.

[mullenswrc]

From what I've seen in most tests the Tesco 99 fuel has been shown to be the best widely available pump fuel. BP Ultimate 102 is the best pump fuel money can buy but it's not exactly widely available.

Ive never heard/seen BP 102. Do they sell it from pumps as usual?

[Daniel]

Ive never heard/seen BP 102. Do they sell it from pumps as usual?
You wouldn't be alone.

It's on sale at a very small amount of stations at the moment

http://www.bp.com/genericsection.do?categoryId=6621&contentId=7017179

Here's where it's sold

http://www.bp.com/sectiongenericarticle.do?categoryId=9009087&contentId=7016865

[mullenswrc]

You wouldn't be alone.

It's on sale at a very small amount of stations at the moment

http://www.bp.com/genericsection.do?categoryId=6621&contentId=7017179

Here's where it's sold

http://www.bp.com/sectiongenericarticle.do?categoryId=9009087&contentId=7016865

Thats really interesting. It says it in a trial period and if its in demand they will sell it more places. I hope it kicks off.

Anyone know how much it is?

[Daniel]

Thats really interesting. It says it in a trial period and if its in demand they will sell it more places. I hope it kicks off.

Anyone know how much it is?
About £2.50. No.... really :)

[Rollo]

From what I've seen in most tests the Tesco 99 fuel has been shown to be the best widely available pump fuel. BP Ultimate 102 is the best pump fuel money can buy but it's not exactly widely available.

"Best"? What was this based on? Particulates?

I think I remember reading somewhere that the reason that Brent Sweet Crude in particular was used as a standard for pricing was that as a light crude it required the least amount of refining to get it to petrol qualities and also contained methyl tert-butyl ether which is a nice lead-napthalate replacement.

In general my Ka runs more evenly on a 91 than a 95RON fuel, then again most cars built after about 1998 have octane sensors which will adjust the mapping accordingly anyway.

[Daniel]

"Best"? What was this based on? Particulates?

I think I remember reading somewhere that the reason that Brent Sweet Crude in particular was used as a standard for pricing was that as a light crude it required the least amount of refining to get it to petrol qualities and also contained methyl tert-butyl ether which is a nice lead-napthalate replacement.

In general my Ka runs more evenly on a 91 than a 95RON fuel, then again most cars built after about 1998 have octane sensors which will adjust the mapping accordingly anyway.
Best as in power gains.

[airshifter]

1 Have you heard of shell V-power?

Yes


2 Do you sometimes/regularly purchase Shell V-power or fuels that give higher performance (if so specify)

At time I purchase higher octane fuels. Having tried several I get best mileage locally with Amoco (now BP) so that is what I usually buy.


3 Do you think Shell V-power would increase the performance of your car?

Not above any other decent fuel of the same octane rating.


4 Would you buy Shell V-power if they lowered the price?

I would buy it if the price was lower than fuels of the same MPG return and octane rating, as long as it remained a decent quality fuel.


5 In a situation where you were forced to buy a high performance fuel brand would you choose Vpower over other products?

No.

[airshifter]

In general my Ka runs more evenly on a 91 than a 95RON fuel, then again most cars built after about 1998 have octane sensors which will adjust the mapping accordingly anyway.

Rollo,

Are you saying that your car actually runs smoother on the lower octane gas?

That is one aspect of using higher octane that I can notice in at least two of our vehicles. The idle quality in particular seems better with higher octane, especially if it is not combined with a timing advance in the case of one vehicle.

On some vehicles the relearn time of the computer might affect the operation, but most computers relearn fairly quickly.



Here in the US we use a different octane rating system, and most pump gas can only be had at 93 or lower octane.

[Wilderness]

1. Yes.
2. Occationally.
3. I cannot tell the performance difference based on butt dyno.
4. Yes, if they lowered the price to a very competitive level.
5. No, not based on performance alone.

[Rollo]

Rollo,
Are you saying that your car actually runs smoother on the lower octane gas?


Yes.
Two factors at play here:

1. My Ka (as with every single car built in the past 25 years) is fitted with knock sensors. These report back to the ECU which makes slight changes to the voltage passing through the spark plugs.
2. I had a set of "cold spark plugs" fitted. This prevents pre-ignition and detonation of vapours in the combustion chamber.

Why is all this relevant to a lower octane rating? Basically the higher the number, the slower the burn rate. Since my Ka has a standard base rate nominally of 90RON, then 91RON is not far off.

http://motormouth.com.au/newsletters/0605.htm

In general, the smoothest running of your engine will be closest to what the manufacturer specifies. Running higher or lower octane rated fuel than the manufacturers settings produces less power than stated.

If anyone should know what the best rated petrol for the engine is, it's the people who made the bloody car. Petrol companies charge higher prices for higher octane petrol so of course they want you to buy it.

[Daniel]

*snip*

2. I had a set of "cold spark plugs" fitted. This prevents pre-ignition and detonation of vapours in the combustion chamber.

*snip*

If anyone should know what the best rated petrol for the engine is, it's the people who made the bloody car.

Surely if they made the bloody car they'd have specced the best plugs for the car?

[Zico]

From the link Daniel provided..


http://www.bp.com/sectiongenericarticle.do?categoryId=9009565&contentId=7018404

"Engine control systems with active knock control generally have accelerometers fitted to the engine block or head that help detect detonation or "knock", which is a form of uncontrolled combustion. Knock can seriously damage an engine. The detection of knock then instructs the engine control system to reduce engine performance by adjusting the engine boost and/or ignition (spark) advance, while optimising the fuelling. This reduces the combustion pressure and temperature in the cylinder so the fuel-air charge doesn't detonate any more.
Performance on demand If the active knock system is capable, I think it’s a good idea to calibrate to a higher octane than the market would generally use. For example, if you want to use regular 95 octane unleaded, the active knock control can adjust down to give the right level of performance without damaging the engine. But when you put 97 (or 102!) octane fuel in, you'd get the full benefit of that performance – basically, performance on demand, depending on the quality of the fuel that you put in."

So am I correct in thinking that as my Pugs engine has active knock control ie, ECU is programmed with either retarded ignition and/or different maps for both 95 and 98 RON It explains my earlier findings with regards to my improved performance, smoother running and better mpg?

I accept that most cars wont benefit but I still maintain that mine does and see the above as confirmation of my own findings... or could it be down to something else?

Sorry if this is off-topic..

[Daniel]

Well my 504 would go further on bp ultimate over normal unleaded. It also had a habit of dieseling sometimes when i ran low octane petrol. I know low octane petrol isn't strictly the cause of dieseling but higher octane petrol seemed to solve it. I don't think the benefits are merely all performance related. My 504 was a carby engined car so didn't of course remap itself to perform better on high octane fuel. But it did run better and seemed to go further.

[airshifter]

Yes.
Two factors at play here:

1. My Ka (as with every single car built in the past 25 years) is fitted with knock sensors. These report back to the ECU which makes slight changes to the voltage passing through the spark plugs.
2. I had a set of "cold spark plugs" fitted. This prevents pre-ignition and detonation of vapours in the combustion chamber.

Why is all this relevant to a lower octane rating? Basically the higher the number, the slower the burn rate. Since my Ka has a standard base rate nominally of 90RON, then 91RON is not far off.

http://motormouth.com.au/newsletters/0605.htm

In general, the smoothest running of your engine will be closest to what the manufacturer specifies. Running higher or lower octane rated fuel than the manufacturers settings produces less power than stated.

If anyone should know what the best rated petrol for the engine is, it's the people who made the bloody car. Petrol companies charge higher prices for higher octane petrol so of course they want you to buy it.


I can't speak for certain on cars outside the US market, but of all cars I know of here the ignition timing is changed by the knock sensors, not the voltage through the coils and plugs. I agree completely that without the ability change timing there is no gain unless the cars active sensors can advance it, but if the car is reacting to the knock sensor then the octane used is not high enough for that specific condition and performance is being lost.

Most vehicles react to the knock sensors by an immediate timing retard of X degrees. Less timing = less power. Many vehicles will also store this information and not allow timing to advance as much for a set number of drive cycles in the relearn process.

Colder heat range plugs can lessen detonation, but if too cold can also prevent proper burn and increase deposits.



As a note, it would be interesting to see how changes in octane ratings and fuel formulations between countries actually affect performance. Here in the US they use a rating combined from the RON number and the MON number. RON rating is a true rating of octane as it was defined, but MON rating adds more load and heat type variables, which closer simulate driving condition extremes.

[airshifter]

From the link Daniel provided..


http://www.bp.com/sectiongenericarticle.do?categoryId=9009565&contentId=7018404

"Engine control systems with active knock control generally have accelerometers fitted to the engine block or head that help detect detonation or "knock", which is a form of uncontrolled combustion. Knock can seriously damage an engine. The detection of knock then instructs the engine control system to reduce engine performance by adjusting the engine boost and/or ignition (spark) advance, while optimising the fuelling. This reduces the combustion pressure and temperature in the cylinder so the fuel-air charge doesn't detonate any more.
Performance on demand If the active knock system is capable, I think it’s a good idea to calibrate to a higher octane than the market would generally use. For example, if you want to use regular 95 octane unleaded, the active knock control can adjust down to give the right level of performance without damaging the engine. But when you put 97 (or 102!) octane fuel in, you'd get the full benefit of that performance – basically, performance on demand, depending on the quality of the fuel that you put in."

So am I correct in thinking that as my Pugs engine has active knock control ie, ECU is programmed with either retarded ignition and/or different maps for both 95 and 98 RON It explains my earlier findings with regards to my improved performance, smoother running and better mpg?

I accept that most cars wont benefit but I still maintain that mine does and see the above as confirmation of my own findings... or could it be down to something else?

Sorry if this is off-topic..


Of all systems I have ever seen hard data on, active timing control is reactive to knock and other various inputs, not proactive. This means simply that the computer can advance timing within limits until the knock sensor tells it that timing is advanced too far for the conditions.

Almost all vehicle systems use tables of some sort that store minimums and maximums, some of which are controlled by other inputs to some extent. These tables and controls will vary even by region often, as vehicles often have a number of different "programs" designed for differing climates or fuel formulations. They call it many different things, but on some vehicles a code is visible on the ECU/ECM/whatever that company calls it. That code represents the specific programming in that system.

Because there are so many variables in driving styles, loads, weather conditions, vehicle condition, etc I would say that it's probably never safe to say that "any 1998 Ka" will benefit from higher octane fuel. Depending on the computer codes it may or may not. It may even only benefit under certain specific conditions and no other time. Short of dyno runs to show power increases or lack of, about the only thing a person can readily get data on themselves is fuel consumption.

Since octane rating changes the energy content of gas very little, if you get better MPG from higher octane than it's probably due to the timing being advanced more on a regular basis. And if that is the case, then the system within your car, with your driving conditions and variables, will benefit to some point with higher octane.


On our small car, I get no benefit that I can track from higher octane, though it does prevent a small ping I get when the knock sensor comes into play. On my truck I can advance base timing, and get a higher MPG return with higher octane if I adjust the timing accordingly.

[Magnus]

As I pointed out before: it is reasonable to expect a slighlty rougher run if you use higher octane in combination with adaption control; variations in the combustion is easier to notice if they occur at a high advance than a low.
Regarding knocksensors, SAAB, amongst others, used measure the resistance between the gap in the sparkplug(actually the ionization), setting the advance accordingly, thus not using a acceleratormetering device(which is actually listening to a ping between 10 and 15 kHz).
Normally you get most out of your engine between 17-20 degreees BTDC, with a base timing of 5-15 degrees.
An old trick, which you can use if you are afraid that your motor pings/knocks is to drive it up a hill at a high gear; the lower the rev and the higher the load/gear the more tendency to nock. In boats you have this situation all the time, it sounds like someone is pouring nails of some metal plate.
higher revs causes less tendency to knock, as does colder weather, more fueland various different aspects.

Many do not know what knock is, allthough it is widelly spoken upon, a brief description for the one interested: When the fuel/air mixture is ignited a flame starts to spread from the spark. When the flame develops(it is very thin) the pressure of the combustion chamber rises, the highest pressure of the unburnt fuel/air mixture is naturally reaching a higher end pressure the closer it is to the wall, i.e cylinder, of the combustion chamber. If the pressure gets to high, that is if you have started your fire to early, the energy within the yet unburned air/fule self ignites. The speed of this self ignition is enough to be called a detonation.
The burn rate of the original flame is 25-30 m/s, depending on design, whilst the speed of the self ignition is up to 300 m/s. This energy is not possible to use, and may cause damages to piston, rods and parts of the combustion chamber.
There is another kind of knock aswell, this knock is produced due to hot spots. It maybe an overheated exhaust valve, some carbon residues or a faulty plug, maybe because of wrong heat number; one of the main characteristics of a plug is the ability o remove heat from the combustion chamber.

There is a correlation between rev and burnrate, but just so far. On many high rev engines the flame is still in progress when you open the exahaustvalve, thus causing loud sensations. This is the case for example in Formula One and many dragsters.

Generally it is better to have the sparkplug in the center of the combustion chamber. One of the best combustion chambers is the typical Hemi engine, so called due to its hemispherical combustion chamber.

This area is very interesting, not least because parts of it are very complex and not yet fully understood, despite that we have even succeeded in photograhing the phenomena. Swirl of the combustion chamber puts other issues in the basket along with different alloys and their specific heat capacity and ability to transport heat to the cooling liquid or through radiation heat.

I better stop before I really get going :)

[airshifter]

Interesting about the Saab. It seems as though they are using spark demand as a monitor for engine load if I'm understanding it correctly.

I think in general the problem with "rules" of timing and octane issues are that there are far too many variables to use a general rule. Materials used within the engine itself, along with chamber and piston design, valve configuration, ignition system capacity, rod ratios, general bore and stroke variables and more account to just the mechanical side of the equation.

How all those factors weigh in with all the various load and fueling issues adds even more complexity. Rolling and wind resistance, aero drag, transmission ratios, type and spacing, weight range of the vehicle use, terrain, weather, driving style and many others then further affect how the timing curve can be used.

To again add a host of variables you have the differing sensors and the way that vehicle uses them within it's computer system.


As a general rule, over the years I've decided to disregard any general rules regarding timing and octane relationships, as general rules must only apply to the vehicles that fit them.

[Daniel]

Interesting about the Saab. It seems as though they are using spark demand as a monitor for engine load if I'm understanding it correctly.

I think in general the problem with "rules" of timing and octane issues are that there are far too many variables to use a general rule. Materials used within the engine itself, along with chamber and piston design, valve configuration, ignition system capacity, rod ratios, general bore and stroke variables and more account to just the mechanical side of the equation.

How all those factors weigh in with all the various load and fueling issues adds even more complexity. Rolling and wind resistance, aero drag, transmission ratios, type and spacing, weight range of the vehicle use, terrain, weather, driving style and many others then further affect how the timing curve can be used.

To again add a host of variables you have the differing sensors and the way that vehicle uses them within it's computer system.


As a general rule, over the years I've decided to disregard any general rules regarding timing and octane relationships, as general rules must only apply to the vehicles that fit them.
Theories are wonderful things aren't they :) If all the theories on engines and such were 100% true and all encompassing somone would have built the most powerful engine or most efficient engine possible years ago.

Like you say there are so many different factors that for each situation and application the solution is somewhat different.

[Zico]

Regarding knocksensors, SAAB, amongst others, used measure the resistance between the gap in the sparkplug(actually the ionization), setting the advance accordingly, thus not using a acceleratormetering device(which is actually listening to a ping between 10 and 15 kHz).

I believe SAAB were in the process of developing a Variable Compression engine (SVC) before being taken over by GM, who shelved the project due to cost.
This engine used a technique that dynamically alters the volume of the combustion chamber (Vc) to change the compression ratio by replacing the typical one-part engine block with a two-part unit, with the crankshaft in the lower block and the cylinders in the upper portion. The two blocks are hinged together at one side (imagine a book, lying flat on a table, with the front cover held an inch or so above the title page). By pivoting the upper block around the hinge point, the Vc was modified. In practice, the SVC adjusted the upper block through a small range of motion, using a hydraulic actuator.

Very original and interesting idea which would have had its own technical difficulties, pro's and cons.

Engine design and innovations really deserves a thread of its own.. would make for very interesting reading... for me at least.

[Rollo]

Surely if they made the bloody car they'd have specced the best plugs for the car?

Ford have specced 3 types of plugs depending on the main usage of the car depending on if the car is mainly going to be used in the city, on the motorway or a halfway plug.

There are different plugs for Germany as well where the road speeds are higher.