98 or 95?

Posted: Tue Feb 02, 2010 1:57 pm

Yes US fuel drops down to 87?

I always feed mine Shell Optimax but tbh i've never noticed any difference in fuel economy. However when i ran it on 95 when they'd run out I got a load of idle problems and it ended up costing me Ł700 for 2 new O2 sensors and a Maf +labour.

Now it's super or none at all!

Posted: Tue Feb 02, 2010 2:00 pm

That's because you've had yours MTM remapped to ONLY run on 98RON. Soon as you do that the engine timing cannot adjust.

Posted: Tue Feb 02, 2010 2:08 pm

Of course it can dont be silly, if it didnt adjust the timing you would end up with serious detonation and destroy engines. Im sorry buy sounds like someone at Audi doesnt really know what they were talking.

Posted: Tue Feb 02, 2010 2:33 pm

Stock Audi can adjust downwards, just not upwards. Same with stock Porsche's (unless you have them remapped).

Posted: Tue Feb 02, 2010 2:47 pm

Yes, but you just said that an RS6 remapped on 98 wouldnt not adjust down to 95, which isnt true, it would be pretty bad for the engine if it didnt.

It also seems stupid to me for Audi in a "green" world to release all the specifications of the car to a lower rated fuel, using the better fuel they would be able to give better CO2 emissions for the power and there for the manufactures overall CO2 rating would be lower. (Not saying they didnt do this, especially if they state 95 in the manual, but still a stupid imo.)

Only one way of finding out and that is to RR on 98/99 and RR on 95. I would bet that on 95 a standard RS6 on 95 would pull timing more than on 98/98.

Also on other thing that might be worth considering is if the manual is same across allboards, if so, from what I remember americans 91 is similar to our 95 and upwards and 95 is similar to out 98/98.

Posted: Tue Feb 02, 2010 3:05 pm

Bad indeed. I don't think a few fill-ups with 95 would be too harmful on a remapped engine. If you only had 91 available (like you took the car to Italy) then you would need to carry some octane additive with you. I know loads of Porsche tuners that recommend this if you go to a country that doesn't have 98 and can be as low as 91.

Posted: Tue Feb 02, 2010 11:49 pm

where from ??!!!

Posted: Wed Feb 03, 2010 12:23 am

Tesco 99 or VPower only for me

Posted: Fri Feb 12, 2010 8:34 pm

Dang and I just got my Shell Vpower card thingy.
I could have bought the wife a Christmas present from the saving if I'd bought 95 since I first had the car.

Posted: Fri Feb 12, 2010 9:34 pm

i run only on branded fuel and were possible V-power, would never buy fuel from the likes of tesco or morrisons as they buy there fuel on the open market and as cheap as possible. using shit fuel will cause all manner of problems from idle issues plugs not burning properly and most costly of all injector failier. we dont get the tesco 99 down here so cant comment on that but generally there fuel is crap

Posted: Fri Feb 12, 2010 9:41 pm

V-Power or T99 for me... have run 95/99 pre and post mapping and the car is obviously happier on the higher.

Alex, I can only suggest you try it and make your own mind up, please don't tell me you're worried about the Ł5 a tank nor the engineering factors of safety on your cars componentry. Speak to Sean at AMD or Minhea at MRC.. also for piece of mind maybe Audi again.

Posted: Thu Mar 11, 2010 9:06 pm

Surely the whole pooint is bettter combustion gives more power, higher rom gives this

103 ROn, tried it once in my B5 on the track, yes please!!!!

Posted: Fri Mar 12, 2010 12:04 am

Only Shell V-Power or Tesco 99 Ron for me as well

Posted: Fri Mar 12, 2010 1:04 am

^^^ Like Nudenut says.

99 (99% of the time), followed by 97 and if on empty in the depths of Cornwall a slurp of 95 till I can get back to civilisation (never a full tank).

Posted: Sat Apr 03, 2010 3:22 pm

I have been putting in super more in the RS6 recently. I have noticed that although there doesn't seem to be any extra power, the engine sounds and feels a LOT smoother.

Given Tesco 99 is part bioethanol, has anyone had any problems with this? Some stories I have heard about bioethanol fuels in other cars are a little scary (timing issues, not starting etc).