Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Ady on 09 February 2014, 10:01:02

Title: Petrol, does it make a difference.
Post by: Ady on 09 February 2014, 10:01:02
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 

 
Title: Re: Petrol, does it make a difference.
Post by: 05omegav6 on 09 February 2014, 11:15:28
Shell V power and Tescos Ultimate both make a difference to the way the car picks up and the mpg :y 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 :y

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 :y

New car is only getting V power...
Title: Re: Petrol, does it make a difference.
Post by: SIR Philbutt on 09 February 2014, 23:00:39
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  ???
Title: Re: Petrol, does it make a difference.
Post by: flyer 0712 on 09 February 2014, 23:57:40
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.
Title: Re: Petrol, does it make a difference.
Post by: Keith ABS on 10 February 2014, 07:38:38
  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
Title: Re: Petrol, does it make a difference.
Post by: TheBoy on 10 February 2014, 08:29:26
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
Title: Re: Petrol, does it make a difference.
Post by: andrew38 on 10 February 2014, 09:32:29
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.
Title: Re: Petrol, does it make a difference.
Post by: Sir Tigger KC on 10 February 2014, 12:41:02
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....  :-\
Title: Re: Petrol, does it make a difference.
Post by: andrew38 on 10 February 2014, 12:55:28
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.
Title: Re: Petrol, does it make a difference.
Post by: TheBoy on 10 February 2014, 17:16:55
Glad both of mine are running on fartgas then :)
Title: Re: Petrol, does it make a difference.
Post by: GastronomicKleptomaniac on 10 February 2014, 20:16:44
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...
Title: Re: Petrol, does it make a difference.
Post by: 05omegav6 on 10 February 2014, 20:20:10
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 :y

The extra mileage gained justifies the extra cost. Any performance benefits are free 8)
Title: Re: Petrol, does it make a difference.
Post by: andymp on 10 February 2014, 23:56:54
Shell V power diesel makes a noticeable difference too... ???
Title: Re: Petrol, does it make a difference.
Post by: Rog on 11 February 2014, 10:21:54

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  :o

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


Title: Re: Petrol, does it make a difference.
Post by: 2woody on 11 February 2014, 11:15:37
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
Title: Re: Petrol, does it make a difference.
Post by: Kevin Wood on 11 February 2014, 11:58:40
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.
Title: Re: Petrol, does it make a difference.
Post by: 2woody on 11 February 2014, 12:40:32
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.
Title: Re: Petrol, does it make a difference.
Post by: Rog on 11 February 2014, 12:46:55
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
Title: Re: Petrol, does it make a difference.
Post by: GastronomicKleptomaniac on 11 February 2014, 16:33:13
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.
Title: Re: Petrol, does it make a difference.
Post by: aaronjb on 11 February 2014, 16:40:02
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 ;D
Title: Re: Petrol, does it make a difference.
Post by: kevinp58 on 11 February 2014, 20:33:24
I only use v-power nitro now as the mig feels so much more responsive and smoother  :y
Title: Re: Petrol, does it make a difference.
Post by: 2woody on 11 February 2014, 20:53:56
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 ?
Title: Re: Petrol, does it make a difference.
Post by: cd 2.2 on 11 February 2014, 23:21:39
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. :D
Title: Re: Petrol, does it make a difference.
Post by: ajsphead on 12 February 2014, 08:29:22
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.
Title: Re: Petrol, does it make a difference.
Post by: GastronomicKleptomaniac on 12 February 2014, 08:37:58
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  ;D It's going to feel strange working on him on Sunday...

It also frightening how easily I slipped into calling the Omegas "him"...
Title: Re: Petrol, does it make a difference.
Post by: 2woody on 12 February 2014, 10:17:41
well I never knew that was you......!