[HighlandPete]

Originally Posted by beemerbird

Why because I didn't bother putting V power in the 330i when I had it back in 2006, and the 330i engine will happily run on 95 RON?

May be it would have really been 'happier' on RON 98... seeing as it was designed around RON 98, although it can run on lower RON ratings at decreased power and increased fuel consumption.

HighlandPete

[pjs]

In last 6k miles, only had to put cheap fuel in once. No idea if it makes any difference, but no idea what the previous owner put in it for 3 years, so i've bought the marketing guff about the detergents as well. Giving the car more hammer lately, but still averaged over 25mpg

[beemerbird]

Originally Posted by HighlandPete

May be it would have really been 'happier' on RON 98... seeing as it was designed around RON 98, although it can run on lower RON ratings at decreased power and increased fuel consumption.

HighlandPete

I tried a few tank fulls and seriously, the car never displayed any degree of 'happiness' and to my knowledge that engine wasn't designed to run on 98 RON specifically according to the manual and details on the fuel cap. It is not a highly tuned engine per se.

MPG improvements I noticed were a whopping 2 mpg at best on a long run.....great eh lol.

[Swiller]

Originally Posted by Don Miaggie

Tesco 99 everytime i can, V power occasionally.

Agree. Only discovered the tesco stuff recently and its the best out there i reckon. Not sure if it has the same cleansing qualities of the vpower/bp ultimate. Spend £50 on shopping and i think you get 5p off a litre making it competetive with usual unleaded at motorway service stations.

Happy to say that i achieved 39 mpg in a 330i N52 on a 180 mile run up the m4 recently with a tank full of tesco 99 (cruise locked at 75-80mph). The car felt slightly more responsive with a bit more fizz under the foot vs the v power/bp ultimate. With a 95 ron i get about 36-37mpg doing the same trip.

[beemerbird]

Originally Posted by Swiller

Happy to say that i achieved 39 mpg in a 330i N52 on a 180 mile run up the m4 recently with a tank full of tesco 99 (cruise locked at 75-80mph). The car felt slightly more responsive with a bit more fizz under the foot vs the v power/bp ultimate. With a 95 ron i get about 36-37mpg doing the same trip.

Bloody hell man, how on earth did you manage those average mpg figures. The absolute BEST I ever saw on mine was 34 mpg having had the torture of travelling through one of those bloody 50 mph average speed check roadworks on the motorway. My constant average was always around 28 mpg, even after re-setting the OBC. My motorway crusing speed is somewhat different to yours though. My car was bought July 2006 but had a build date of November 2005 under the bonnet so which N series engine would that be?

[willhollin]

Originally Posted by beemerbird

Bloody hell man, how on earth did you manage those average mpg figures. The absolute BEST I ever saw on mine was 34 mpg having had the torture of travelling through one of those bloody 50 mph average speed check roadworks on the motorway. My constant average was always around 28 mpg, even after re-setting the OBC. My motorway crusing speed is somewhat different to yours though. My car was bought July 2006 but had a build date of November 2005 under the bonnet so which N series engine would that be?

That's because you used the cheaper fuel.

[SoYank]

Originally Posted by creepy coupe

Is your V Power 99 oct out there M335i? thought your fuel was knocked back.

M335i is in New York where the octane is calculated differently. They use an average of RON and MON and the results is an advertised octane rating about 4-5 points lower than here. For example, the 98 RON here is about 93 (R+M)/2 there; 95 here is about 91 there. I don't recall ever seeing anything over 93 octane in the states but I generally don't look too hard.

Just for your edification.

[beemerbird]

Originally Posted by willhollin

That's because you used the cheaper fuel.

Will, I tried a few tanks of super unleaded and as I said before, it made 2 mpg difference so wow 30 mpg overall for the extra cost and no noticeable increase in performance - yeah great!

I have a heavy right foot but I'm with Carl on this fuel economy lark. Drive the car and enjoy it, buy a car whereby you can afford the fuel bills or not.

Fu*k me that's still better than the mpg I'm getting now..............on V POWER

[NFS]

I tend to use the V-Power stuff even though I am almost certain that it's pure marketing bollocks.

[RichJ]

In my 330i N53 (272hp), V power definitely makes the car more responsive, it feels more powerful and provides a slight increase in mpg. The manual states it should be run on 98RON to achieve optimum power etc.

[Imran@Evolve]

V Power most definitely makes a difference on the 335i. We have not tested it on the 330i but I am sure it will make a difference over using 95 RON fuel.

I will post up some dyno graphs to show the difference the fuel makes on the 335i. There is really no point buying one and putting 95 RON fuel in it as you are cheating yourself out of some power!

[HighlandPete]

Originally Posted by beemerbird

I tried a few tank fulls and seriously, the car never displayed any degree of 'happiness' and to my knowledge that engine wasn't designed to run on 98 RON specifically according to the manual and details on the fuel cap. It is not a highly tuned engine per se.

MPG improvements I noticed were a whopping 2 mpg at best on a long run.....great eh lol.

Assuming you are referring to the N52 engine, then it was designed for RON 98 as the preferred fuel. (BMW data)

HighlandPete

[doughboy]

Originally Posted by beemerbird

that engine wasn't designed to run on 98 RON specifically according to the manual and details on the fuel cap. It is not a highly tuned engine per se.

These days the engines aren't designed with a need for a particulare grade, they have a range over which the ECU will adapt and operate at the optimum conditions without detonation.

So using the best fuel within that range will make best use of the profile available.

My N52 330i was markedly better on V power than 95 ron, crisper throttle response, better midrange pull, and an extra final surge from 6krpm to the redline which was none existant on 95ron due to he ignition timing restraint.

The 335i petrol cap states 95 - 100RON I think, so 1 more RON please to make best use of it!!

[HighlandPete]

Obviously BMW have to design with a range of fuels in mind, but the optimum performance of most of the petrol engines are specified as designed for RON 98. With the lower grades referenced.

When I had the M62 V8 engine in the E39 540i, the performance on Shell Optimax (at the time) was always better pick up, more urgent mid range, smoother running and better economy, compared to RON 95 fuel, if you didn't use the full performance gains. In fact the cost was virtually identical, as a cost per mile.

HighlandPete

[Imran@Evolve]

I have added a dyno comparison between 95 and 99 RON here

[zltm089]

ah damn it!!!...i voted the wrong type...

i always use tesco super unleaded...just to collect points! lol

[Jamese93]

I always use Tesco - the car seems happier on it, much smoother and responsive - the same was true of my previous car but same engine so would have been (even though manual versus current auto), although in my older 325ti (2002) it didn't make that much difference, but that was was really pretty damn fast - only reason it made 0-60 at 6.9 seconds (from recollection) was it simply ran out of revs just before 60 and even with a lightening quick gearchange tyou would have lost a second or so. Perhaps as it was an older engine design it made little difference? OT I know but ah well......