I tend to use regular 95 with occasional V-Power, it gives 1-2 mpg more but I haven’t done the maths to work out if it's worth it. It might idled more smoothly and be a little sharper on pick up (which would make sense as the timing should be mapped forward slightly with higher octane) but I could be kidding myself.
Survey - What Grade of Fuel Do You Use?
- Thread starter Z4 Pilot
- Start date
It's all a bit 'Emperors Clothes' for me. I just fill with whatever petrol there is at the garage and so far I can report that when I press the accelerator the car goes forward. Maybe its because my car is getting on a bit I dont really care,..even if there is some discernible difference there's no point putting fine wine in a spritzer.
E85 said:
Opinion noted and duly discarded! Used V power for best part of a year then thought I'd give Shell's new fuel saver 95 RON a try. Yes rising fuel costs were a factor but the reality is it's made no difference. I'm no cheapskate but I also don't like wasting money. If I could see a genuine difference I would continue to use it.
Dev said:
Standard grades in the colonies are 87/89/91 with some stations offering 93/94 as a super premium grade. Overall the same stuff as Europe, just a different method of measuring it, in NA we use (RON+MON)/2 which is about 4 points lower than RON for most grades.
http://en.wikipedia.org/wiki/Octane_rating
I run 94 (98 RON) when I can find it otherwise I'll settle for 91 (95 RON). The car seems to like it although I haven't tried to quantify what difference there is if any.
I currently use:
Shell V-Power for the 1992 Scirocco (higher octane required for my 16v)
Shell unleaded for the 1988 BMW 635 (will need to go to super once the new fuel comes in)
Shell V-Power for the 1992 Scirocco (higher octane required for my 16v)
Shell unleaded for the 1988 BMW 635 (will need to go to super once the new fuel comes in)
Been using 97 RON for a couple of weeks, and strangely the mpg has dropped by about 2 mpg, despite no change to driving style. I agree it seems to idle slightly more smoothly when cold, but I just haven't noticed any other difference. I'm switching back to 95 now, probably Shell as there's some garages on the way into London that are a good 3p less than in my home town.
Thread revival.
I generally only use 97/98 Ron. Usually shell v-power, occasionally bp ultimate.
Have to say, for some reason it always feels "nicer" with bp ultimate. - completely no science/objective measure and probably all in my head as I can't define how it feels "nicer" or why. But where I am there seems to be an abundance of shell garages so mainly gets v-power.
Probably only a fiver difference per tank compared to 95/supermarket fuels which is nothing really over course of a week/fortnight. Am I getting ripped off/falling for marketing/wasting money ?? - possibly, but I don't mind, I know it would niggle at me if I was using the 95ron.
Also. . . I may have imagined this but sure I read somewhere(possibly owners handbook) that recommended fuel is 97ron or above for the M
I generally only use 97/98 Ron. Usually shell v-power, occasionally bp ultimate.
Have to say, for some reason it always feels "nicer" with bp ultimate. - completely no science/objective measure and probably all in my head as I can't define how it feels "nicer" or why. But where I am there seems to be an abundance of shell garages so mainly gets v-power.
Probably only a fiver difference per tank compared to 95/supermarket fuels which is nothing really over course of a week/fortnight. Am I getting ripped off/falling for marketing/wasting money ?? - possibly, but I don't mind, I know it would niggle at me if I was using the 95ron.
Also. . . I may have imagined this but sure I read somewhere(possibly owners handbook) that recommended fuel is 97ron or above for the M
Shell V Power for me too 
For my "Location" in my Avatar I was going to put " generally in a Shell Garage"
For my "Location" in my Avatar I was going to put " generally in a Shell Garage"
99 RON here. Mostly Tesco Momentum. Some Shell stations still seem to think it's ok to sell 97 rated VPower which is annoying...
I just read this:
It turns out that in Europe, the octane number posted is determined by the RON method (if you live in Europe, check the small print on the gas pump next time you fill 'er up. Wait, filling it up requires taking out a loan nowadays...). In the USA, the number posted is according to the "(R+M)/2" method. Turns out that this is simply the average of the RON number and the MON number. So, would the MON number typically be lower than the RON number? The answer is....yes! Apparently, for modern fuels, the difference between RON and MON (also called sensitivity) is about 10 (RON is higher than MON). Knowing this, we can now calculate the following:
87 octane in the USA = 92 octane in Europe
89 octane in the USA= 94 octane in Europe
92 octane in the USA = 97 octane in Europe
Go figure, huh? It seems these regular and premium fuels have roughly the same octane rating after all.
:roll:
It turns out that in Europe, the octane number posted is determined by the RON method (if you live in Europe, check the small print on the gas pump next time you fill 'er up. Wait, filling it up requires taking out a loan nowadays...). In the USA, the number posted is according to the "(R+M)/2" method. Turns out that this is simply the average of the RON number and the MON number. So, would the MON number typically be lower than the RON number? The answer is....yes! Apparently, for modern fuels, the difference between RON and MON (also called sensitivity) is about 10 (RON is higher than MON). Knowing this, we can now calculate the following:
87 octane in the USA = 92 octane in Europe
89 octane in the USA= 94 octane in Europe
92 octane in the USA = 97 octane in Europe
Go figure, huh? It seems these regular and premium fuels have roughly the same octane rating after all.
:roll:
Ive been keeping a record of economy and average speed, miles done, things like that.
Tried various fuels from standard 95, 97, and even the Tesco 99 stuff. Not been able to prove any significant differences on fuel type vs economy.
Strangely average mph for the tank used isn't that significant either.
Mind you for a while with the old Z4 I had cracks in the exhaust manifold and that was an effect.
Tried various fuels from standard 95, 97, and even the Tesco 99 stuff. Not been able to prove any significant differences on fuel type vs economy.
Strangely average mph for the tank used isn't that significant either.
Mind you for a while with the old Z4 I had cracks in the exhaust manifold and that was an effect.
I am a doctor in the NHS and i practice evidence based medicine. Pharmaceutical companies have arguably the most aggressive marketing strategies of any industry and are forever trying to convince the everyone to buy the "improved formulas of proven drugs. Unless there is a proven reason in a reputable trial i see little reason to change. This is why my doctors i know buy supermarket paracetamol rather then neurofen as the evidence the drug companies use are sketchy at best. Some of the studies already done on the forum are better. so for now i will stick to 95 RON. i will always be open for definitive proof high RON is better but until such evidence is convincing regular stuff for me