F10 M5 fuel

F10 M5 fuel

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Discussion

666 SVT

1,052 posts

240 months

Monday 4th May 2015
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A friend of mine spends his day doing tuning and dyno testing of mainly Ford Focus ST and RS models.
He often sees the ECU pull the timing with low octane fuel to protect the engine so full power is not available. Pretty sure this
would also be the case with a 550bhp+ engine.

Wills2

22,839 posts

175 months

Monday 4th May 2015
quotequote all
The fact that the M5 makes full power on 98ron fuel is not at issue, BMW state that in black and white.

666 SVT

1,052 posts

240 months

Monday 4th May 2015
quotequote all
Never seen 98 available at any garage I have ever been to? Regular by me is either 95 or 97 depending on the garage.

rjn21

289 posts

164 months

Monday 4th May 2015
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Tesco 99 - http://www.tescopfs.com/our-fuel
Shell 99 - http://en.wikipedia.org/wiki/Shell_V-Power

Unhelpfully Shell don't quote a RON number for V Power on their website, but at the pump it's advertised at 99. The predecessor Shell fuel Optimax was 98 RON. Currently there is no widely available 98 RON in the UK, Tesco and Shell do 99, most other "Super Unleaded" is 97 RON.

BMW F10 M5 is mapped to achieve maximum ignition advance at the detonation point of 98 RON fuel. 95 RON fuel can be used without any adverse affects, save that the ignition timing will be retarded slightly, so slightly less power and fuel economy will result.
For a stock F10 M5, fuel of a RON level above 98, will of itself produce no more power than 98 RON fuel, but 99 is the only >97 fuel widely available.

Edited by rjn21 on Monday 4th May 18:14

Wills2

22,839 posts

175 months

Monday 4th May 2015
quotequote all
666 SVT said:
Never seen 98 available at any garage I have ever been to? Regular by me is either 95 or 97 depending on the garage.
I've already said/mentioned that previously on this thread, the choice in the UK is 95/97 or 99 (Shell/Tesco) only the 99 will give you full power as it is over specced.


JMBMWM5

2,292 posts

198 months

Tuesday 5th May 2015
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Wills2 said:
I've already said/mentioned that previously on this thread, the choice in the UK is 95/97 or 99 (Shell/Tesco) only the 99 will give you full power as it is over specced.

Having owned both LCI M5 and now M6 GC CP I find that 97 is just great and the best fuel I have found for both cars is ESSO 97.

W8PMC

3,345 posts

238 months

Tuesday 5th May 2015
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Pretty sure it even says on the Fuel Filler cap that you should use a minimum of 98 but 95 can be used if no 98+ available.

To put in perspective & i can't recall if the M5 has this in the manual, but newer Audi RS's state in the manual you shouldn't apply full throttle unless the car is running with at least 98Ron in the tank.

I only put Shell Nitro+ or Tesco 99 in mine.

zeDuffMan

4,055 posts

151 months

Tuesday 5th May 2015
quotequote all
I may be wrong but I was under the impression all petrol cars sold in the UK have to be able to run on 95 RON minimum.

The ECU will adjust timing depending on the octane level to prevent pinking, quickly winding back if using a lower quality fuel and taking time to build back up when you begin using higher quality stuff.

Unless there's something wrong with your car (and the engine is tuned to make use of it) 99 RON will be better than 95 or 97.

jrinns

370 posts

183 months

Tuesday 5th May 2015
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Will diesel work in the M5?

Wills2

22,839 posts

175 months

Tuesday 5th May 2015
quotequote all
JMBMWM5 said:
Wills2 said:
I've already said/mentioned that previously on this thread, the choice in the UK is 95/97 or 99 (Shell/Tesco) only the 99 will give you full power as it is over specced.

Having owned both LCI M5 and now M6 GC CP I find that 97 is just great and the best fuel I have found for both oes nocars is ESSO 97.
Good for you buddy, but you're down on power not that it matters in the slightest with these beasts.




BobSaunders

3,033 posts

155 months

Wednesday 6th May 2015
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jrinns said:
Will diesel work in the M5?
Yes, they recommend a mixed blend. More torque innit.

theboss

6,917 posts

219 months

Monday 25th May 2015
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Wills2 said:
JMBMWM5 said:
Wills2 said:
I've already said/mentioned that previously on this thread, the choice in the UK is 95/97 or 99 (Shell/Tesco) only the 99 will give you full power as it is over specced.

Having owned both LCI M5 and now M6 GC CP I find that 97 is just great and the best fuel I have found for both oes nocars is ESSO 97.
Good for you buddy, but you're down on power not that it matters in the slightest with these beasts.



It's an odd one for sure (97 vs 99) but having run my car exclusively on Vpower and Tesco 99 so far (5000 miles) I had no choice but to fill it with Esso 97 last night... and 100 miles later having forgotten about the refuel and any resulting differences I honestly found myself thinking the car felt slightly more lively than usual at the top end. Very odd indeed!

JMBMWM5

2,292 posts

198 months

Monday 25th May 2015
quotequote all
theboss said:
It's an odd one for sure (97 vs 99) but having run my car exclusively on Vpower and Tesco 99 so far (5000 miles) I had no choice but to fill it with Esso 97 last night... and 100 miles later having forgotten about the refuel and any resulting differences I honestly found myself thinking the car felt slightly more lively than usual at the top end. Very odd indeed!
I met a guy on holiday in Jamaica and he says ESSO 97 is the best fuel out there, and he works for SHELL!!!, he is a scientist.
I must say if ESSO was close to me it would be my choice.