Discussion
Thats is my thinking. I collect it tomorrow and I am not to sure but I think the ECU has been upgraded and remapped so 97 is what i will run until I can get it checked out, I will then blend my own (its what I do for a living). There is a lot of rubbish talked about the additives in V-power and all the other over priced fuels and the mapping as the percentages of methaanols, toluenes and other additives changes on every refinery run depending on chemical costs. So a bit of advise for all the guys that think they must use a certain grade, if it makes you feel better then keep doing it but you dont need to, F1 runs on normal pump fuels!
sunoco69 said:
brb said:
in france the 95 is rare, we have E85 with ethanol. so, I put 98.
but I observe that the engine run a little better with 95
Do you have any problems with erroding of seals or fuel lines? Ethanol is fairly nasty to those.but I observe that the engine run a little better with 95
Blu3R said:
Chapppers said:
If it's mapped for 95 why use anything else? That's all I've ever and will ever put in.
I'm with you. When I do eventually get mine remapped it'll be on 95 anyway, why plan every journey around petrol stations? I've got more important things to worry about in my life!
V-Power and the like is ~5p/l or around 27p per gallon.
21mpg, 10,000 miles = 476 gallons = £128 over the year.
On a £65k car with £1-2k servicing costs per year etc. I'm surprised people worry about this sort of thing!....
Mine lives off V-Power, primarily because of this Evo test (from 2002).
21mpg, 10,000 miles = 476 gallons = £128 over the year.
On a £65k car with £1-2k servicing costs per year etc. I'm surprised people worry about this sort of thing!....
Mine lives off V-Power, primarily because of this Evo test (from 2002).
Evo Mag Issue 44 June 2002 said:
Can Shell's new super unleaded really clean your engine and improve performance? We put three tong termers on a 1500 mile exclusively Optimax diet to find out.
You've probably seen the TV ads for Optimax. There's one with a little yellow fish ducking through a sub aqua rush hour and a Jeremy Clarkson voiceover telling you how Shell's new fuel can make your car nippier when it counts. Another features Michael Schumacher reinforcing the link with Ferrari, to whom Shell supplies F1 fuel. Cute stuff, strong endorsements, but does Optimax really deliver what it promises? Specifically, does it improve engine response and can it really clean up your engine?
That's what we set out to discover, using three of our long term test cars as guinea pigs the Civic Type it, M Coupe and XJR R. Respectively four, six and eight cylinders, high output engines all, the Honda and BMW efficient normally aspirated units, the Jag boosted by a supercharger. All will run on regular 95 octane unleaded but have knock sensors which adjust to take account of higher octane super unleaded petrol (SULP).
The test ran for at least 3000 miles on each car, the first 1500 on unleaded other than Optimax, the second 1500 exclusively on the new Shell fuel. Before switching to Optimax, all three cars were performance tested and the condition of their inlet valves was inspected using a bore scope. After the Optimax regime, the tests were repeated.
One of the claims for Optimax is that it cleans up an engine's inlet valves. The exhaust valves don't collect deposits to the same degree, which might seem odd, but the spent gases passing them are hot, burnt (largely) and moving fast. However, a mixture of unburnt fuel and air gathers behind the head of the inlet valve, waiting for it to open. Shell says that heavy constituents in other fuels can leave deposits on the backs of the inlet valves, and the poorest quality fuels leave the most, sometimes leading to a build up of tar like gunge within 1000 miles.
These deposits are a problem because they interfere with the flow of fuel/air mixture into the cylinder. The ideal combustion, and thus optimum power, is provided by an orchestrated, finely atomised, swirling mixture, and the inlet valve's heads have been painstakingly shaped to help provide this. If they're gunked up, combustion efficiency and therefore performance is affected.
We shall see, but Optimax should improve performance because of its higher octane rating, a minimum of 98 RON compared with 97 for other SULPs and 95 for standard unleaded. Even if the clean up claims aren't borne out by our tests, Shell's commitment to providing 98 RON fuel is good news for drivers of performance cars because it's been increasingly hard to find SULP in the last couple of years.
Pre Optimax Inspection
The BMW is the first to have its spark plugs removed to give access for the bore scope. The M Power straight six is a very efficient engine, boasting almost 100bhp per litre, and its keeper, co editor Meaden, has fed it a mixture of regular and super unleaded from big brand forecourts for the 20,718 miles it has covered.
The bore scope reveals that it is incredibly clean the valves, ports, and pistons gleam like new and you can even see the fine machining marks on the inlet ports. Shell's technical Coffins are impressed. There are no deposits for Optimax to remove, so any gain in performance will be down to its clean burning and higher octane rating.
The Honda's high revving 16 valve four cylinder engine has a similarly high specific output 99bhp per litre. It has clocked fewer miles, just 9271, in the hands of freelance contributor Brett Fraser who admits that the Civic doesn't always get the best fuels. Super unleaded is rare in Norfolk where he lives and its usual diet is regular 95 octane unleaded which, Fraser confesses, often comes from his local supermarket.
Inside, it's not a pretty sight. 'That's quite a heavy deposit,' says the Shell technician snooping around the Honda's valves. There's a tar like rim of goo on the head of one of the inlet valves and most of the others show some deposits. There's plenty for Optimax to work on, and there should be a noticeable contrast between performance on 95 unleaded and the 98 octane rated Shell fuel.
The Jaguar's 4 litre 32 valve V8 makes 93bhp per litre with the help of a supercharger. I was fairly confident that it wouldn't be as dirty as the Honda; I've run it for most of its 34,001 miles and in my hands it has never been anywhere near a supermarket filling station. It gets SULP when I know I'm going to be using the performance but if it's only going to be cruising long distances, I use branded 95 octane unleaded.
Oh dear. More grubbiness than even the Honda in places. The valves of number five cylinder (shown) were particularly encrusted. Strangely, on another cylinder one of the pair of inlet valves is much more heavily caked with deposits than the other, even though both are fed by the same inlet tract. Again, plenty for Optimax to get stuck into.
The performance tests we carried out focused on in gear flexibility. Standing start acceleration brings in too many variables driver technique, tyre temperature, surface condition, etc. The ingear test is much more consistent and repeatable. It simply involves full throttle acceleration from 20mph to the engine limiter or 100mph.
Honda Civic Type R (Brett Fraser)
Miracle performance enhancers? The Devil's work. To be treated with rabid cynicism, even when created by a respected giant like Shell. But once a camera had shown the Civic s coked up valves, it seemed worth giving this super fuel a fair go. Previously I'd be skinflinting by sticking in supermarket juice. The Honda seemed to be okay on it, so would Optimax make a difference? After a couple of tankfulls, and despite my cynicism, I could feel a change. The R was livelier in the mid range; brisk overtaking could be achieved in a gear higher than normal, and full on go arrived with more gusto. Yet economy scarcely moved from the pre Optimax average of 32.5 mpg. More poke, undamaged economy, cleaner internals Optimax makes an impressive case for itself. Its extra cost may put me off using it for every fill up but I have since found myself pulling up at the Optimax pump more often that not.
Jaguar XJR-R (John Barker)
I expected any change in performance in the Jag to be harder to detect than in the BMW or Honda because of its auto 'box. You don't get the instant bite, that sharp throttle response that you do with a manual. You don't tend to use the full performance of the XJR very often, either it's plenty fast enough on part throttle. That said, after about 1000 miles on Optimax something had happened. It was subtle but undeniable the engine was running more smoothly. As more miles piled on it began to feel friskier, too, more alert to both small and large throttle openings. Kick down response felt snappier and the V8 picked up more cleanly. Pre Optimax, fuel consumption was steady at 19mpg or so. On the new diet this dipped slightly to around 18.5, which was disappointing, though by the time it had completed 1500 miles on Optimax, that figure had recovered to 19mpg. It has to be the fuel of choice for serious drivers.
BMW M Coupe (Richard Meaden)
I’d never been particularly fussy about the fuel I put in the M Coupe, especially as BMW doesn't stipulate super unleaded. That said, whenever I treated it to 97 octane it felt keener, but I didn't expect a big improvement running on Optimax. The reality was a surprise, with more instant response, whether singing away above 6000rpm or lugging below 3000rpm. One thing Optimax couldn't eradicate was the M Coupe's intermittent stammer as it pulls through the rev range - not a misfire, more a micro hesitancy at around 4000rpm - but it did smooth the sensation a little. Fuel economy deteriorated slightly, the 1500 miles or so on Optimax equating to 23.2mpg compared with the 1500 immediately prior to Optimax at 23.9mpg, although I suspect this is due to a subconscious effort to drive faster with the new Shell fuel in the tank. Will I continue to use it? Well, put it this way, my new Caterham Fireblade hasn't tasted anything else....
Post Optimax Inspection
The inlet valves of the Honda were clearly a lot cleaner after 1500 miles on Optimax. There were a few very light deposits but the additives had got rid of most of them. It was the same story with the Jaguar, which had done about 3000 miles on the Shell fuel, with only minor deposits on a couple of valves. There wasn't much point looking inside the BMW's engine again it couldn't have been cleaner if it had just been built.
Our objective performance tests revealed improvements for all three cars. The Honda showed the most dramatic and conclusive gains, most especially in fifth and sixth gears. PreOptimax, it had been drinking regular unleaded, remember, where the other two had been supping a fair bit of super. Across each of the 20mph increments in fifth, the Honda was about a second faster, the best improvement being the reduction in the 60 80mph time of 1.19sec, from 7.80 to 6.61. The average incremental improvement in sixth was two thirds of a second; in third and fourth it was more marginal at just 0.25sec or so.
The Jaguar was a little less conclusive, gaining just a couple of tenths over the increments up to 80mph, rising to just under half a second for the 80 l00mph stretch. I had expected more, given that subjectively it seemed sharper responding and smoother running.
The performance of Meaden's M Coupe was improved by a similar margin to the Jaguar. There wasn't much gain in third gear but in fourth it was as much as half a second more rapid over each of the increments. And that's just through the higher octane rating of Optimax there was no cleaning up to be done.
Conclusion
Our tests show that Optimax does what Shell claims. It cleaned up the dirty valves of the Honda and Jaguar and improved their measured performance. It also made the BMW quicker. Subjectively it works too, improving the smoothness, response and driveability of all three cars in the opinion of their keepers. These are all modern cars with knock sensors, though; older cars without them may need to have their timing adjusted, as they would if they were to take advantage of any super unleaded fuel.
What is also suggested by our tests is that, just as there is no such thing as a cheap tyre, there is no such thing as cheap fuel. You get what you pay for. With most unbranded (i.e. supermarket) fuels that means fewer additives and the buildup of more performance sapping deposits.
You've probably seen the TV ads for Optimax. There's one with a little yellow fish ducking through a sub aqua rush hour and a Jeremy Clarkson voiceover telling you how Shell's new fuel can make your car nippier when it counts. Another features Michael Schumacher reinforcing the link with Ferrari, to whom Shell supplies F1 fuel. Cute stuff, strong endorsements, but does Optimax really deliver what it promises? Specifically, does it improve engine response and can it really clean up your engine?
That's what we set out to discover, using three of our long term test cars as guinea pigs the Civic Type it, M Coupe and XJR R. Respectively four, six and eight cylinders, high output engines all, the Honda and BMW efficient normally aspirated units, the Jag boosted by a supercharger. All will run on regular 95 octane unleaded but have knock sensors which adjust to take account of higher octane super unleaded petrol (SULP).
The test ran for at least 3000 miles on each car, the first 1500 on unleaded other than Optimax, the second 1500 exclusively on the new Shell fuel. Before switching to Optimax, all three cars were performance tested and the condition of their inlet valves was inspected using a bore scope. After the Optimax regime, the tests were repeated.
One of the claims for Optimax is that it cleans up an engine's inlet valves. The exhaust valves don't collect deposits to the same degree, which might seem odd, but the spent gases passing them are hot, burnt (largely) and moving fast. However, a mixture of unburnt fuel and air gathers behind the head of the inlet valve, waiting for it to open. Shell says that heavy constituents in other fuels can leave deposits on the backs of the inlet valves, and the poorest quality fuels leave the most, sometimes leading to a build up of tar like gunge within 1000 miles.
These deposits are a problem because they interfere with the flow of fuel/air mixture into the cylinder. The ideal combustion, and thus optimum power, is provided by an orchestrated, finely atomised, swirling mixture, and the inlet valve's heads have been painstakingly shaped to help provide this. If they're gunked up, combustion efficiency and therefore performance is affected.
We shall see, but Optimax should improve performance because of its higher octane rating, a minimum of 98 RON compared with 97 for other SULPs and 95 for standard unleaded. Even if the clean up claims aren't borne out by our tests, Shell's commitment to providing 98 RON fuel is good news for drivers of performance cars because it's been increasingly hard to find SULP in the last couple of years.
Pre Optimax Inspection
The BMW is the first to have its spark plugs removed to give access for the bore scope. The M Power straight six is a very efficient engine, boasting almost 100bhp per litre, and its keeper, co editor Meaden, has fed it a mixture of regular and super unleaded from big brand forecourts for the 20,718 miles it has covered.
The bore scope reveals that it is incredibly clean the valves, ports, and pistons gleam like new and you can even see the fine machining marks on the inlet ports. Shell's technical Coffins are impressed. There are no deposits for Optimax to remove, so any gain in performance will be down to its clean burning and higher octane rating.
The Honda's high revving 16 valve four cylinder engine has a similarly high specific output 99bhp per litre. It has clocked fewer miles, just 9271, in the hands of freelance contributor Brett Fraser who admits that the Civic doesn't always get the best fuels. Super unleaded is rare in Norfolk where he lives and its usual diet is regular 95 octane unleaded which, Fraser confesses, often comes from his local supermarket.
Inside, it's not a pretty sight. 'That's quite a heavy deposit,' says the Shell technician snooping around the Honda's valves. There's a tar like rim of goo on the head of one of the inlet valves and most of the others show some deposits. There's plenty for Optimax to work on, and there should be a noticeable contrast between performance on 95 unleaded and the 98 octane rated Shell fuel.
The Jaguar's 4 litre 32 valve V8 makes 93bhp per litre with the help of a supercharger. I was fairly confident that it wouldn't be as dirty as the Honda; I've run it for most of its 34,001 miles and in my hands it has never been anywhere near a supermarket filling station. It gets SULP when I know I'm going to be using the performance but if it's only going to be cruising long distances, I use branded 95 octane unleaded.
Oh dear. More grubbiness than even the Honda in places. The valves of number five cylinder (shown) were particularly encrusted. Strangely, on another cylinder one of the pair of inlet valves is much more heavily caked with deposits than the other, even though both are fed by the same inlet tract. Again, plenty for Optimax to get stuck into.
The performance tests we carried out focused on in gear flexibility. Standing start acceleration brings in too many variables driver technique, tyre temperature, surface condition, etc. The ingear test is much more consistent and repeatable. It simply involves full throttle acceleration from 20mph to the engine limiter or 100mph.
Honda Civic Type R (Brett Fraser)
Miracle performance enhancers? The Devil's work. To be treated with rabid cynicism, even when created by a respected giant like Shell. But once a camera had shown the Civic s coked up valves, it seemed worth giving this super fuel a fair go. Previously I'd be skinflinting by sticking in supermarket juice. The Honda seemed to be okay on it, so would Optimax make a difference? After a couple of tankfulls, and despite my cynicism, I could feel a change. The R was livelier in the mid range; brisk overtaking could be achieved in a gear higher than normal, and full on go arrived with more gusto. Yet economy scarcely moved from the pre Optimax average of 32.5 mpg. More poke, undamaged economy, cleaner internals Optimax makes an impressive case for itself. Its extra cost may put me off using it for every fill up but I have since found myself pulling up at the Optimax pump more often that not.
Jaguar XJR-R (John Barker)
I expected any change in performance in the Jag to be harder to detect than in the BMW or Honda because of its auto 'box. You don't get the instant bite, that sharp throttle response that you do with a manual. You don't tend to use the full performance of the XJR very often, either it's plenty fast enough on part throttle. That said, after about 1000 miles on Optimax something had happened. It was subtle but undeniable the engine was running more smoothly. As more miles piled on it began to feel friskier, too, more alert to both small and large throttle openings. Kick down response felt snappier and the V8 picked up more cleanly. Pre Optimax, fuel consumption was steady at 19mpg or so. On the new diet this dipped slightly to around 18.5, which was disappointing, though by the time it had completed 1500 miles on Optimax, that figure had recovered to 19mpg. It has to be the fuel of choice for serious drivers.
BMW M Coupe (Richard Meaden)
I’d never been particularly fussy about the fuel I put in the M Coupe, especially as BMW doesn't stipulate super unleaded. That said, whenever I treated it to 97 octane it felt keener, but I didn't expect a big improvement running on Optimax. The reality was a surprise, with more instant response, whether singing away above 6000rpm or lugging below 3000rpm. One thing Optimax couldn't eradicate was the M Coupe's intermittent stammer as it pulls through the rev range - not a misfire, more a micro hesitancy at around 4000rpm - but it did smooth the sensation a little. Fuel economy deteriorated slightly, the 1500 miles or so on Optimax equating to 23.2mpg compared with the 1500 immediately prior to Optimax at 23.9mpg, although I suspect this is due to a subconscious effort to drive faster with the new Shell fuel in the tank. Will I continue to use it? Well, put it this way, my new Caterham Fireblade hasn't tasted anything else....
Post Optimax Inspection
The inlet valves of the Honda were clearly a lot cleaner after 1500 miles on Optimax. There were a few very light deposits but the additives had got rid of most of them. It was the same story with the Jaguar, which had done about 3000 miles on the Shell fuel, with only minor deposits on a couple of valves. There wasn't much point looking inside the BMW's engine again it couldn't have been cleaner if it had just been built.
Our objective performance tests revealed improvements for all three cars. The Honda showed the most dramatic and conclusive gains, most especially in fifth and sixth gears. PreOptimax, it had been drinking regular unleaded, remember, where the other two had been supping a fair bit of super. Across each of the 20mph increments in fifth, the Honda was about a second faster, the best improvement being the reduction in the 60 80mph time of 1.19sec, from 7.80 to 6.61. The average incremental improvement in sixth was two thirds of a second; in third and fourth it was more marginal at just 0.25sec or so.
The Jaguar was a little less conclusive, gaining just a couple of tenths over the increments up to 80mph, rising to just under half a second for the 80 l00mph stretch. I had expected more, given that subjectively it seemed sharper responding and smoother running.
The performance of Meaden's M Coupe was improved by a similar margin to the Jaguar. There wasn't much gain in third gear but in fourth it was as much as half a second more rapid over each of the increments. And that's just through the higher octane rating of Optimax there was no cleaning up to be done.
Conclusion
Our tests show that Optimax does what Shell claims. It cleaned up the dirty valves of the Honda and Jaguar and improved their measured performance. It also made the BMW quicker. Subjectively it works too, improving the smoothness, response and driveability of all three cars in the opinion of their keepers. These are all modern cars with knock sensors, though; older cars without them may need to have their timing adjusted, as they would if they were to take advantage of any super unleaded fuel.
What is also suggested by our tests is that, just as there is no such thing as a cheap tyre, there is no such thing as cheap fuel. You get what you pay for. With most unbranded (i.e. supermarket) fuels that means fewer additives and the buildup of more performance sapping deposits.
Evo Mag Issue 44 June 2002 said:
That's what we set out to discover, using three of our long term test cars as guinea pigs the Civic Type it, M Coupe and XJR R. Respectively four, six and eight cylinders, high output engines all, the Honda and BMW efficient normally aspirated units, the Jag boosted by a supercharger. All will run on regular 95 octane unleaded but have knock sensors which adjust to take account of higher octane super unleaded petrol (SULP).
Nobles don't.It would be interesting to see what the additives have done to various Nobles I guess specially if some of us are running 95 and some always 97+ but what the article also highlights is that different engines use the same fuels in different ways.
An italian tune-up every now and then could produce the same results.£128 is an extra (albeit cheap) trackday, and a lot of people will go to a lot of trouble to save that on insurance.
Edited by Chapppers on Friday 13th May 11:19
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