53 replies to this topic

[Jake Blues]

If you've got a 70's low compression engine it's not going to be particularly bothered what you put in it

Not sure if that's true....any engine would run better on "better" fuel surely?

[mini93]

depends what addatives are in it i guess? its not going to do as much for a carb'ed car than a injection one that efficiently meters fuel entering the cylinder rather than a carb just throwing fuel through a hole which isnt anywhere nearly atomised as FI where each fuel drop has more surface area to burn and the higher octain resisting knock on the higher compression and forced induction engines.

i dont use higher octane fuel, i just use lead replacment (leaded head) with added octain booster...not sure how effective it is but the megajolt hasnt been mapped correctly yet anyway so i wouldnt see much improvment

[Ethel]

If you can't generate the conditions where a higher octane fuel would be needed then why would it give any benefit? Octane is about resisting spontaneous combustion so you can run higher combustion pressures, with more oxygen, to burn more fuel - or burn what fuel you do have hotter without detonation.

We'd need to know if the fuels had different stoichiometric or calorific values to see the whole picture.

I'm not saying you can't see any benefit, but there must be a limit as to how far you can advance the ignition before pushing the piston in the wrong direction before it gets to tdc starts to lose you noticeable efficiency.

[bartmag79]

There must be more than "one big tank". When the Buncefield Depot in Hemel went up We still had fuel and that was obviously being stored elswhere in the country. After reading this i am going to try running on BP ultimate as I work next to a BP garage and is easy for me to do. I will also get my nectar points.

[AndrewJ530]

Filled up my yaris last night with v power so i'm going to do a test and see what my mpg is.

I've done a few calculations (being an engineer i like to do calculations lol) which show that for the fuel to give me better mpg, i have to do 80 miles more just to match standard 95ron petrol. I'm not sure whether i'll get these extra 80 miles out of this tank so i'm a bit dubious about v power giving better mpg at the moment. This might be due to the fact it was £1.09/ litre so if the price drops then it might prove cost effective.

I'll report back in a couple of weeks once i've used the tank and give you the quoted mpg figures .

Cheers,

Andrew

[roga]

I find V-Power makes a noticeable difference in my Mpi both in terms of fuel economy and power.

With more modern engines I haven't noticed a lot of difference and don't bother paying the extra for v-power, I have used the Tesco 99 stuff in the modern car and it's fine but again no massive difference - never tried it in my Mpi though.

[twrminisport]

might sound stupid but shell v power is good and so it bp ultimate but the petrol on the market with the highest octane content at the moment is actually tesco's i was really suprised when i heard but yeah it is i use it in my mini and in my bikes and it better than ultimate for sure and in not sure about v-power

[AndrewJ530]

Well ladies and gentlemen, i've used 2 tanks of shell v power, one with a long journey to alton towers and one for backwards and forwards to work (12 miles each way). And i can conclude that shell v power does give slightly higher mpg figures (50.2 instead of 44.4). This was in a 2003 toyota yaris, 998, 16 valve, injection.

However it's still not cost effective. This is due to the fact that it costs too much! It's just plain cheaper to use 95 ron petrol from the supermarkets.

However, this is subject to evidence on whether it will be cost effective in a carbed mini. To be honest i think it wont work but thats my personal opinion. It did make my car run a bit smoother and a slight increase in torque (didn't have to change down to overtake properly on motorways) but i still stand by my results for the mpg test. These attribute i think will occur in a mini aswell but it's not worth the extra pennies.

Cheers,

Andrew

[Joloke08]

Update Should of really updated this last month :what the hell:
Been running Boris on Premium Fuel since the L2B now and have no intention to go back to standard 95 Ron

He does seem that little bit nippier on premium i dont know if he does any more to the gallon to be honest i never checked before :oops:

But he does seem to run better,cant quite put my finger on whats changed but to Mine n Sams mind hes became a little bore responsive and less beckward at comming forward when you hit the throttle if you get my drift? :thumbup:

Our first fill up we discovered though we thought we were out of fuel there was still a couple of gallons in there
So it was a bit of a mix but that soon worked its way through and soon we were running just on Premium

I did start out using Shell V power as there was only one BP around here i could find but Sam found another and generally weve carried on using BP Ultimate unless we get caught short miles from a BP then we will use whatever premium is available but only enough to get us to another BP and we havnt once had to use standard unleaded

So all in all i think its been worth changing to premium its only a couple of quid extra per tank id rarther pay that little bit extra and pamper his engine

Huggz
Jodie