Bp Ultimate Or Regular Fuel? Any Differences?

[GJN]

On a slightly different track: How much difference (if any) does DSC make to 0-60 time?

[Rich_D]

Well it can run on standard, it just runs s**t. I'd not have used regular had I had the choice but it was either that or get out and push.

Sure there was a minimum octane rating for the M3?

I once had to use 95 in my 200SX leaving Santa Pod, it was mapped for SUL, but I was running on fumes and there was only 95 available, so I put a small amount in and drove slowly off boost until I could get some V-Power, it ran like crap too.

[Rich_D]

On a slightly different track: How much difference (if any) does DSC make to 0-60 time?

How long is a piece of string?

Depends if you break traction or not, as if you do it kills the power and will harm times, it will vary depending on the car, the tyres, the road surface, etc...

[Gaz]

Sure there was a minimum octane rating for the M3?

I once had to use 95 in my 200SX leaving Santa Pod, it was mapped for SUL, but I was running on fumes and there was only 95 available, so I put a small amount in and drove slowly off boost until I could get some V-Power, it ran like crap too.

According to an online manual for the M3:

I'm not sure if AKI is different to RON though? And that looks like an American manual so again may be different in the UK.

[Dr T]

I looked into this ages ago using tescos finest, judging such small power increases is impossible thru the seat of your pants so I just drove as normal and used more miles per litre as an indication of a more efficient fuel, and by virtue of being more efficient, I reasoned the car must be making the same power from less fuel, so the same amount of fuel should yeild more power. Anyway results of 10 tanks worth are here

http://www.e46zone.c...-a-318i-8v-m43/

Edited January 14, 2013 by Dr T

[Dr T]

I had another example with my audi. A valve in the vacuum system broke which essentially meant the car couldn't restrict the airflow into the manifold enough when idling, the result was hunting for revs at idle and throwing up of fault codes saying its running lean. Running tescos 99 masked the issue, so broken valve + 95ron = lumpy and lean idle bit broken valve +99ron = no issues. Replaced the valve and it runs fine on both fuels. So clearly the higher ron fuel allows the engine to use more air for a given volume of fuel. More air used should translate to more power developed. Its just the power difference is too small for your butt the measure.

Edited January 14, 2013 by Dr T

[Rich_D]

According to an online manual for the M3:

I'm not sure if AKI is different to RON though? And that looks like an American manual so again may be different in the UK.

What does it say in your own handbook?

[Gaz]

What does it say in your own handbook?

God knows, I'm 135 miles away from it

[mit]

I used to use premium in the 330 but purely because it's a slightly cleaner fuel and is meant to be better for the engine in the long run. On the M3 I've used premium everytime but one, and the one time I had to use 95 ron fuel it ran like a dog. Very lumpy and felt lower on power.

I'd say performance wise though on a 318, you wont notice much real world difference in the short term.

I wonder whether it would have run ok if you'd done the throttle adaptation reset after that fill-up? Just curious though... I personally find my car feels nicer with super and I definitely get better economy around town - the extra 20 or 30 miles per tank is definitely noticeable!

[GJN]

How long is a piece of string?

Depends if you break traction or not, as if you do it kills the power and will harm times, it will vary depending on the car, the tyres, the road surface, etc...

Optimum wheel slip for maximum acceleration is around 5%, not 0% so if DSC begins operation at anything over 0% then it will, in theory, reduce acceleration. Is the traction control element of DSC optimised or not ?

[Gaz]

Yes it very well may have done, I'm not sure. If I get stuck having to use it again I'll give it a shot.

[Rich_D]

Optimum wheel slip for maximum acceleration is around 5%, not 0% so if DSC begins operation at anything over 0% then it will, in theory, reduce acceleration. Is the traction control element of DSC optimised or not ?

Depends what version of DSC you have, my old 52 plate 330d was very intrusive, the slightest hint of slip and it kicked in hard, whereas my current 54 plate 330d allows some slip before intervening, it is better IMO

DSC is a suite of electronic driver aids, traction control is just one of them and can be turned off independantly of the rest of the system. A single press of the DSC button (1 light on dash) kills traction control and leaves other parts of the system active, so you can spin the wheels in a straight line, but it kicks in if you go sideways. Pressing & holding the DSC button for 5 secs (2 lights on dash) turns everything off.