Fuel query.

[Mad4slalom]

Morning all, apologies for so many questions. talking to the previous owner of my vette, he used to run 91 octane fuel with no pinging. I think our standard unleaded is 95Ron, do folk use this or go for a premium 98 ron fuel ? My engine is running 10/1 compression pistons btw. Many thanks

 

[Oneball]

91 Octane in the states is the equivalent of super unleaded 97 RON here.

 

[Mad4slalom]

91 Octane in the states is the equivalent of super unleaded 97 RON here.

Really? So shell V power it is then

 

[Robert Craske]

American engines run on much lower octanes as they dont need the higher octanes to try and get more power out of the small engines that we have in Europe which struggle to go up hills. Watch out for the ethanol content as a lot of places are starting to use E10 in the lower octane fuel and if the car sits a lot and does not get flushed through with new fuel as a normal car does you can get corrosion problems in your fuel system. The ethanol absorbs water like a sponge.

 

[Oneball]

Their octane rating isn’t the same as ours. I think you add 5 to get from US to UK. Have a google fir a conversion.

When I’ve been in the states 91 is sold as premium unleaded. But some places also sell a super premium.

See what works. Super unleaded here usually has a lower ethanol content which is a bonus.

 

[Roscobbc]

It's been independently proven that Shell VPower does actually improve power output - OK you'll never notice it - at perhaps 1-2% increase in power (so perhaps 10 bhp at best on a late model Vette) - I remember when running my new engine-in and using 'ordinary' 4 star when I couldn't get to a Shell garage. With 4 star 'running-on' when switching the engine off was a major issue. At the time I put it down to the 'freash' piston crowns and combustion chamber having 'sharp' edges and retaining combustion temperatures causing the issue. Reverting to Shell VPower more or less eliminated the problem.

 

[Mad4slalom]

It's been independently proven that Shell VPower does actually improve power output - OK you'll never notice it - at perhaps 1-2% increase in power (so perhaps 10 bhp at best on a late model Vette) - I remember when running my new engine-in and using 'ordinary' 4 star when I couldn't get to a Shell garage. With 4 star 'running-on' when switching the engine off was a major issue. At the time I put it down to the 'freash' piston crowns and combustion chamber having 'sharp' edges and retaining combustion temperatures causing the issue. Reverting to Shell VPower more or less eliminated the problem.

Thats interesting thank you. Although the vette is here, it arrived with half a tank of us gas , wating for registration docs from dvla so have not driven it yet other than just in and out of garage and down garden. I have occasioally heard a hint of running on when I switch off but only like a half arevolution,, needs a run and fill up with v Power

 

[kentvette]

Just to put the cat among the pigeons - for the 30 years we've owned the Corvette I've used the cheapest fuel I can get! Supermarket has been the brand and 95 octane.

BUT - for reasons I won't go into, the timing has been set to be a tad "aggressive" in recent years. And, the propensity for anywhere here to replace 95 unleaded with the dreaded E10 means that I've started to put 98 in it. It seems to like it! That said, if your timing is stock then you may not need it. Interestingly, I've never run any of my cars on Shell of any kind because I found that they just don't like it! That may be the way I have tuned them, but I actually thought I had a serious problem in one car, until I switched back to a cheaper fuel.

The key thing is to avoid Ethenol at all costs - the older fuel systems just cannot cope with it and rubber and plastic parts will begin rotting out. Not sure what the situation is over there now, but if you can avoid E10 then do so. Or, add Millers EPS, proven to combat the harmful effects.

 

[Mad4slalom]

Just to put the cat among the pigeons - for the 30 years we've owned the Corvette I've used the cheapest fuel I can get! Supermarket has been the brand and 95 octane.

BUT - for reasons I won't go into, the timing has been set to be a tad "aggressive" in recent years. And, the propensity for anywhere here to replace 95 unleaded with the dreaded E10 means that I've started to put 98 in it. It seems to like it! That said, if your timing is stock then you may not need it. Interestingly, I've never run any of my cars on Shell of any kind because I found that they just don't like it! That may be the way I have tuned them, but I actually thought I had a serious problem in one car, until I switched back to a cheaper fuel.

The key thing is to avoid Ethenol at all costs - the older fuel systems just cannot cope with it and rubber and plastic parts will begin rotting out. Not sure what the situation is over there now, but if you can avoid E10 then do so. Or, add Millers EPS, proven to combat the harmful effects.

Its a minefield out there with regard to getting solid info on fuel grades. The old supermarket fuel is rubbish mantra seems cannot be proven, I have not or never would put it in my cars just in case. But all fuels you would think must be to a certain british stardard so should be up to a certain level of quality.
my local indi garage who sells texaco says v power is no better than what he sells , yet shows customers a gummed up maf sensor and throttle body saying he gets cars in all the time for repair due to using supermarket fuels. He obviously has an axe to grind so not a balanced view. Some say no ethanol in esso premium but only in certain counties not, annoyingly, in devon or cornwall. Glad to hear there is an additive that reduces the harmful effects of ethanol in petrol. You can buy Av Gas at the local airfield sans ethanol but reckon the bill for a vette tankful would make your eyes water

 

[sublimemike]

What do you think you are going to put in the tank? If you are in Devon /Cornwall it is a pain for Esso ethanol free as that's where they don't have it. AV gas with 10-1 compression would be very expensive and not really needed. Depends how much you are going to use the car. If its going to be in your garage for winter not used I would definitely add a fuel additive that combats ethanol. Just don't put any of these E10 fuels in which in time will mean super unleaded for most classic owners that contains 5% Ethanol.

 

[Mad4slalom]

What do you think you are going to put in the tank? If you are in Devon /Cornwall it is a pain for Esso ethanol free as that's where they don't have it. AV gas with 10-1 compression would be very expensive and not really needed. Depends how much you are going to use the car. If its going to be in your garage for winter not used I would definitely add a fuel additive that combats ethanol. Just don't put any of these E10 fuels in which in time will mean super unleaded for most classic owners that contains 5% Ethanol.

Will probably go with V power , cant go with anything till my reg arrives tho, desperate to get on the road all hoses and lines renewed and carb and tank were new during resto so hopefully ethanol proof but will go with an additive and will not leave it standing for more than a couple of weeks. Beach buggy has been fine so far after finishing it 3 years ago , may leave it a month but not longer without a clear out and run up the road.

 

[Roscobbc]

Might be worthwhile 'reading-up' on Avagas - wouldn't want to make the mistake of using leaded on a late model gas with catcon.

The ultimate guide to jet and aviation fuel

In this ultimate guide to jet and aviation fuel, we explore what jet and aviation fuel are, their differences, properties, the various types of jet fuel available, plus much more.

www.total.co.uk

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Avgas | Fuel For Small Piston Powered Aircraft | Shell Global

Avgas is ideal for use in small piston engine powered aircraft, this page summarises the available fuel grades and the history of Avgas.

www.shell.com

 

[Mad4slalom]

Thanks, I wasnt seriously thinking of av gas, just my microlite flying friend mentioned that it was ethanol free. Will try V power.

 

[Roscobbc]

I'm hoping that Anders of Anglo American fuels will do a magazine feature on mixing 103 octane race gas with 4 star to provide a better than 98 octane pump gas.

 

[sublimemike]

That would be interesting...Vpower / Tesco momentum 99 octane, AV gas 101. Those Sunoco fuels don't come cheap but are the biz for high compression motors.