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[Ady]

I've been fueling up at different stations and noticed some perform better than others.

What fuel do you use and does Opitimax or higher octane fuels perform that much better.

Or is it better to use an octane additive with standard petrol.

??

2.6 CDX 

 

[05omegav6]

Shell V power and Tescos Ultimate both make a difference to the way the car picks up and the mpg the mpg gain is somewhat offset by the cost of the fuel though

Some garages are better than others when it comes to tank maintenance though... try and make a note of which fuels have a negative effect and avoid them

Personally, I normally by regular Shell and bung in the odd tank of V power along with a couple of tins of Wynns injector/fuel treatment. If you don't have the Pre Cat codes putting the EML on, then this will help keep them at bay, as will giving the car a decent blast every so often

New car is only getting V power...

[SIR Philbutt]

I see a difference with LPG from different places, thing is the cheapest is the best  it's a gas place not a station.

All the rest are Cheshire gas supplied, but there are differences between them 

[flyer 0712]

I use shell   v.power.....always had trouble with emissions at m.o.t.time to the extent of telling me the cat needed replacing to allowing it to idle for 20 minutes before it just about crept in on limits....now no trouble at all in fact they told me that the emissions are well within limits first time around.So i think it is worth the extra pennies for the v.power.

[Keith ABS]

  If you are having to run at a budget, give it three fills before MOT time with V power etc to help the ommisions levels. Usually super market fuel is not as god as normal stations
Keith B

[TheBoy]

Any car with knock sensors should be able to see some benefit from higher octane fuels.

As to supermarket v branded fuel, I think on petrol its far less noticible than on diesel.

The individual needs to ascertain if the small benefits are worth the expense

[andrew38]

V-Power is very good if you need the high octane stuff for say Japanese imports and bikes, however I have found both the Omega and Corsa run great on Esso especially Supreme, I learn't recently that Supreme is one of the few fuels that are still to not have Ethanol added apart from in South West.

[Sir Tigger KC]

V-Power is very good if you need the high octane stuff for say Japanese imports and bikes, however I have found both the Omega and Corsa run great on Esso especially Supreme, I learn't recently that Supreme is one of the few fuels that are still to not have Ethanol added apart from in South West.

I read recently that the proportion of ethanol added to petrol will increase due to EU rules on using sustainable fuels, however many older engines cannot cope with the extra proportion of ethanol.... 

[andrew38]

Yep you are right, however what a lot of people don't know is that the ethanol content has been rising for a number of years from around 2% to now this year 5%, ethanol though an Octane booster actually causes fuel economy to reduce. At the moment in the UK there is no date for the introduction of E10 though Germany has had it for a couple of years and was not well received, fuel economy will suffer even more as well as any possible damage to seals etc. Not sure if the Omega could ever run on E10.

[TheBoy]

Glad both of mine are running on fartgas then

[GastronomicKleptomaniac]

I will only use supermarket fuel if absolutely desperate - I, like others, have found that I get better mpg from BP Ultimate and the like - so ppm works out roughly the same...

[05omegav6]

I will only use supermarket fuel if absolutely desperate - I, like others, have found that I get better mpg from BP Ultimate and the like - so ppm works out roughly the same...

That's what I found when V Power first came out

The extra mileage gained justifies the extra cost. Any performance benefits are free

[andymp]

Shell V power diesel makes a noticeable difference too...

[Rog]

I'm a total V Power convert. However, be careful. Normally V Power is around 6p per litre more than 95 unleaded, occasionally however you will find a Shell garage that charges as much as 11p more per litre.

I never buy V Power at a motorway service station, simply way too expensive (Actually I never buy anything at a motorway service station for the same reason)

I am cautious about other premium fuels like BP Ultimate, same price as V Power but not nearly as good, 97/98 ron instead of 99. Some supermarkets have a good 99 ron petrol.

Some years ago before V Power replaced Optimax, I was in a focus group where Shell were trying to assess how much they could charge for V Power. Prices as much as 20p over unleaded were bandied about 

I have to hold my hands up and mention that I also buy Shell as I am an avid Air Miles (Avios) collector 

[2woody]

Well, I'm going to go against the grain here and state that despite much trying and some dyno testing, I cannot tell the difference.

Each engine will be set up to run on a certain octane of fuel. In the case of Omega B, that's 95RON. Feeding that same engine with 98RON or higher makes no difference except in very extreme circumstances.

sorry

[Kevin Wood]

Well, I'm going to go against the grain here and state that despite much trying and some dyno testing, I cannot tell the difference.

Each engine will be set up to run on a certain octane of fuel. In the case of Omega B, that's 95RON. Feeding that same engine with 98RON or higher makes no difference except in very extreme circumstances.

sorry

I'd have to agree. Whilst the engine does have knock sensors and the ability to trim timing, I've never seen knock retard active on a non-faulty engine, regardless of fuel, and when it does kick in, it's a limp-home strategy that kills the performance in the event that it finds itself running on weasel-pee. The engine is simply not highly strung enough to suffer any issues on the 95 RON petrol for which it was designed, so it runs with exactly the same ignition advance on that as it does on any high octane petrol. You're never going to get a significant change in performance in that scenario.

My westfield, on the other hand, with 11.5:1 compression and no knock control, really doesn't appreciate 95 RON. (and some petrol marketed as "high octane fuel", for that matter!). So, it does make a difference to the right engine but you need high compression or forced induction, otherwise it's probably a waste of money.

[2woody]

I do use 98RON on trackdays, just to give me that little bit of "overhead" against knock because I know that the engine will get mighty hot on occasion. But it does nothing for the performance at all.

[Rog]

Well . . . . . 

There's no huge difference with my MV6, just a bit

There is a vast and very VERY noticable difference with SWMBOs Volvo 940

[GastronomicKleptomaniac]

I do use 98RON on trackdays, just to give me that little bit of "overhead" against knock because I know that the engine will get mighty hot on occasion. But it does nothing for the performance at all.

Interesting - could it be placebo effect, or perhaps the much-marketed cleaning properties of the fuel making a difference?

 My own unscientific test was to brim the tank of KKP with BP Ultimate, projected range went way higher than it had done in the past, I always suspected the gentle drive to the fuel station would have had a lot more to do with it.

[aaronjb]

My westfield, on the other hand, with 11.5:1 compression and no knock control, really doesn't appreciate 95 RON. (and some petrol marketed as "high octane fuel", for that matter!). So, it does make a difference to the right engine but you need high compression or forced induction, otherwise it's probably a waste of money.

The M3 has a sticker saying "95-98" in the petrol flap door - I've always used V-Power before now, until last night when I was forced to stick regular in (the bingo light was on and the nearest Shell turned out to only have V-Power Diesel and regular UL, which didn't help me much!) .. so far I haven't felt a massive difference, maybe a little flatter at the top end.

The sticker, though, implies the car has a tune for 98 and pulls timing via the knock sensors on anything less - I'm pretty sure both you and Stuart are right for the Omega and it has a tune for 95 and won't add timing over that for 98, just pull timing for fuel worse than 95.. I've never felt any difference in the butt dyno, anyway, and so the Omega gets whatever is cheapest in the area

Well.. I did feel a difference the other week, but that's when it dropped a cylinder or two

[kevinp58]

I only use v-power nitro now as the mig feels so much more responsive and smoother 

[2woody]

My own unscientific test was to brim the tank of KKP with BP Ultimate, projected range went way higher than it had done in the past, I always suspected the gentle drive to the fuel station would have had a lot more to do with it.

do you have a "KKP", too ?

[cd 2.2]

This is an age old debate I guess ... My own experience with my shitron Picasso 1.8sx, I found that if I used supermarket fuel I got around 80 miles less to a tank than I did if I was using say BP unleaded (my own personal favourite since I noticed that their unleaded was actually very noticeably green coloured).
The higher octane fuels I see as a waste of money as my right foot is way too heavy at times and I can't justify the higher price.

[ajsphead]

With the Mtech chip there's definitely a difference between 95 & 98RON. Not so much with power but the engine runs and pulls more smoothly, Also it stopped the annoying little knock rattle on changing up that he did pre and post chip. Chipping did improve it. Chip & 98 RON gets rid of it completely.

[GastronomicKleptomaniac]

My own unscientific test was to brim the tank of KKP with BP Ultimate, projected range went way higher than it had done in the past, I always suspected the gentle drive to the fuel station would have had a lot more to do with it.

do you have a "KKP", too ?

I did have, you've got him now  It's going to feel strange working on him on Sunday...

It also frightening how easily I slipped into calling the Omegas "him"...

[2woody]

well I never knew that was you......!