98 RON Limit on 330Ci Sport

[NTaro]

Fuel cap says 92-98 RON. Shell has 99 (V-power). BP Ultimate has 97. Where do you find 98 around Hampshire/Surrey?

I'm concerned the 98 limit maybe a strict upper limit. I would have thought BMW have a good reason for setting that limit, otherwise why not just write 92+ if it didn't matter (like my last car)? or set a higher upper limit even?

I'm after maximising the performance without causing any short or long term damage. Any advice would be much appreciated.

[furball330i]

i'm pretty sure tesco 'super' is 98... I can't really see v-power ruining your engine to be honest

[steve_n]

99 is absolutely 100% fine in the engine. At the time of manufacture 99 wasn't around as Optimax was only 98 and there was no Tesco 99. You can run it on 95 happily enough too but it was designed to run better on higher octane. You could even run it on 102 if you so wished.

[Silent1]

The upper limit isn't a problem, it's the lower limit, the higher the ron the more resistance to knock, so you can chuck 99/102/15 etc in with no ill effects.

[abarber]

It should be fine tbh, the knock sensor should ensure it's gets some advantage too.

My E90 says 91, 95, 98, 100 or higher on the fuel flap!

[Matt UK]

I put V-Power in my 530i every other tank - I can't really claim the mpg or performance benefits are tangible, but it certainly makes it feel a bit more 'healthy' and 'willing'

Maybe its just the placebo effect though convincing myself to feel better having just handed over my £90

[NTaro]

Matt UK said:

I put V-Power in my 530i every other tank - I can't really claim the mpg or performance benefits are tangible, but it certainly makes it feel a bit more 'healthy' and 'willing'

Maybe its just the placebo effect though convincing myself to feel better having just handed over my £90

To get maximum performance, I've heard that you should not 'dilute' your high quality fuel with a lower grade one. Whether it's true or not, I'm not sure, but to eliminate the uncertainty, surely every other V-powered tank means your car never quite reaches the maximum performance (since there will always be some significant left over lower grade fuel in the tank to "contaminate" the V-power). I can't remember where I read it, but I do seem to recall that the best performance is reached after say at least 4 full tanks of the high quality fuel.

Having said that, I appreciate the V-power has other engine cleaning benefits over supermarket 99 or other lower RON fuel, so your cash isn't wasted.

Anyone know whether V-power 99 is any better performance-wise than BP Ultimate 97 (or vice-versa)? I know V-power has a higher RON value, but higher figures doesn't necessarily translate to better performance, just like you wouldn't judge how good a car is by the size of it's engine!!

[Silent1]

A fuel chemist who doesn't work for shell told me v-power is 10 years ahead of bp ultimate or any other super premium fuel

[Romanymagic]

Run mine on V-power now, I find the car pulls better, response is more instant and generally the whole set up seems happier.

Previously running on supermarket unleaded/super unleaded and the 330 seems to "bog down".

Not convinced on the "placebo effect" of using super unleaded/premimum brand as the wife noticed our car pulled better (her words: it seems more urgent...") and she didn't know about the fuel change etc.

[dcb]

NTaro said:

Anyone know whether V-power 99 is any better performance-wise than BP Ultimate 97 (or vice-versa)? I know V-power has a higher RON value, but higher figures doesn't necessarily translate to better performance, just like you wouldn't judge how good a car is by the size of it's engine!!

Dunno about 97 versus 99, but I know my E39 530 loves 100 or 102 Oktane
instead of usual 98 Oktane when its in Germany.

Not sure the difference between 97 and 99 would be noticeable
or usable in the UK, though.

I suspect you'd have to be really keen and or thrash it
to notice the difference.

[NTaro]

Thanks guys... I've been using BP Ultimate thinking this is how I would get the best performance out of the car... I haven't tried V-power yet, but I will do when I fill up next time.

One thing I have noticed is the lag when I put my foot down... the car does shift eventually, but not the second I put my foot down... there's usually a second or two delay before it accelerates. It had inspection 2 & brake fluid change done about a month ago, so I put it down to the type of fuel I've been using rather than some other problem. Will soon find out if there's another issue.

Those who have a 330i/Ci, is it normal to have a second or two delay before the car starts to shift? or does it respond instantly the moment you accelerate? I noticed that I don't get much of a pull until the revs have reached at least 3000 rpm (or thereabouts). Accelerate below that and it feels sluggish (it's where the lag is most noticeable). This behaviour is what I expect from a diesel engine, not petrol, but would be interested to know whether this is normal or not.

[Pentoman]

Can of worms?
I'm pretty sure it's a known flaw of the 3-series

[Vixpy1]

Silent1 said:

A fuel chemist who doesn't work for shell told me v-power is 10 years ahead of bp ultimate or any other super premium fuel

Well we call it BP Ultiste if that helps

[NTaro]

Pentoman said:

Can of worms?
I'm pretty sure it's a known flaw of the 3-series

Can you provide a link to this known problem? I should mention that this is with a 6-speed manual, not automatic/steptronic.

[rich85uk]

abarber said:

It should be fine tbh, the knock sensor should ensure it's gets some advantage too.

[Pentoman]

NTaro said:

Pentoman said:

Can of worms?
I'm pretty sure it's a known flaw of the 3-series

Can you provide a link to this known problem? I should mention that this is with a 6-speed manual, not automatic/steptronic.

I don't believe it's gearbox dependent.
http://www.google.co.uk/search?hl=en&safe=off&...

[steve_n]

NTaro said:

Thanks guys... I've been using BP Ultimate thinking this is how I would get the best performance out of the car... I haven't tried V-power yet, but I will do when I fill up next time.

One thing I have noticed is the lag when I put my foot down... the car does shift eventually, but not the second I put my foot down... there's usually a second or two delay before it accelerates. It had inspection 2 & brake fluid change done about a month ago, so I put it down to the type of fuel I've been using rather than some other problem. Will soon find out if there's another issue.

Those who have a 330i/Ci, is it normal to have a second or two delay before the car starts to shift? or does it respond instantly the moment you accelerate? I noticed that I don't get much of a pull until the revs have reached at least 3000 rpm (or thereabouts). Accelerate below that and it feels sluggish (it's where the lag is most noticeable). This behaviour is what I expect from a diesel engine, not petrol, but would be interested to know whether this is normal or not.

After a while the electronic throttle learns your driving style and unless you are constantly nailing it the car seems to build in a delay. It's most annoying and I wish it would just do what you ask it to. However, you can reset the throttle by turning the key to position 1 for 10s and then off for 10s before starting the engine. See if you notice any difference.

Mine pulls well enough but like you describe doesn't really start to move until 3k or so. Peak torque is around here so it's no surprise and the power ramps up quickly from 3-6k so I would say it's normal. It is quite a heavy car after all so is never going to be a rocket until it's producing decent power higher up.

Edited by steve_n on Monday 19th July 12:58

[NTaro]

Thanks guys. I did some further searching around the web and came across an old document:

http://home.comcast.net/~jns-johnson/M54-MS43_EDK_...

I'm not sure if this solution is relevant to E46 330Ci Sport as it's not clear how this procedure is linked to which model exactly, but it's very similar to the solution mentioned. Perhaps someone can confirm.

[tgr]

Bringing this back to octane - I have read that the ECU takes a couple of tanks of high octane fuel to get used to it and thus to adjust the timing. Can someone who knows for certain confirm that or correct it? Ta (M52TU)

[NTaro]

I don't know for definite, but I have also read that it takes about 3+ tanks to get the full benefit of high octane.