what petrol to use ?

[lostu 0]

hi,any advice on what's the best make and type of petrol to use in a esprit S3 n/a 1984,also if to use petrol additive what type cheers lostu.

[910Esprit 576]

With the compression of an NA, I would say super unleaded - no additives required.

NB - I recently noticed that my Tesco unleaded has gone from 98 to 99 octane - which must be one of the highest octanes available on the high street.

cheers Steve 84 turbo

[lostu 0]

hi steve,i've been using shell v-power do you think tesco's super is better thanks.

[beagleair 0]

I use avgas! 100 octane and still has lead. Engine seems to love it, but i cant help but wonder if its doing any harm?? time will tell i guess

[910Esprit 576]

Hi Stu

I wondered if Tesco fuel is actually Shell, as most of the other super unleaded seem to be maximum 98 octane. Someone on the forum will know the answer!

cheers Steve

[Kimbers 1,904]

Beware of Tesco fuel, don't forget it was to blame for tens of thousands of cars going pop last year. We had 62 cars in just our garage, they blamed it on a batch they bought from Eastern Europe/Russia.

I use Shell or Jet Super Unleaded.

[USAndretti42 322]

I use avgas! 100 octane and still has lead. Engine seems to love it, but i cant help but wonder if its doing any harm?? time will tell i guess

I would say that Avgas is a bit over the top. The engine doesn't the lead for valve seat lubrication and the lead salts can shorten spark plug life. A regular S3 N/A should be happy with 95 unleaded, methinks.

[Jussi 1]

I've tried Shell formula100, we notice no difference. Shell claims that consumption is less but in my case, no difference.

I have used normal 98E and that's fine, have used that also in my previous race car, which had very high compression ratio.

[Tentenths 1]

I recently noticed that my Tesco unleaded has gone from 98 to 99 octane - which must be one of the highest octanes available on the high street.

In High Street terms that's correct (although BP has 9 UK outlets selling Ultimate 102!). Tesco 99 SUL is still in the process of being rolled out to its filling stations. Currently available from 300 or so but quite a few have yet to switch from 97/98.

i've been using shell v-power do you think tesco's super is better thanks.

This has been debated long and hard on various performance car forums. Frankly, there is little to choose between the two. Some owners/cars/engines favour Tesco 99 SUL and others V-Power. Personally, I use both in the Esprit and the Subaru but for me V-Power has the edge - marginally smoother power delivery and better fuel consumption (latter due to the 5% biethanol content in Tesco's fuel).

I wondered if Tesco fuel is actually Shell

Nope. Tesco's 99 SUL is independently produced and sourced from Greenergy

Beware of Tesco fuel, don't forget it was to blame for tens of thousands of cars going pop last year.

Fair point but pretty sure that problem was caused by standard (95 RON) UL.

[Kimbers 1,904]

Either way they buy as cheap as they can. "Here mate need some dodgy petrol"....."Why yes please 1 Million litres please"

[fenton 0]

SHELL OPTIMAX is the stuff to have. My son races motox and if i remember rightly it is 0.7 octane higher than the next best, and its burning efficiecy is supposed to be the good. Avgas 100/110 will only make your engine perform better if it is set up to run on it, high compression , advanced spark, etc. It could actually make it go slower than super unleaded.

[Tentenths 1]

Optimax now superseded by V-Power

[Advantage 910]

The extra power these expensive fuels can give is only of use at wide open throttle positions. If you're only ever using part throttle (for instance, on the road - going to the shops or stuck in traffic!) the extra perceived bhp gain isn't worth having.

A different matter entirely for track use or if the placebo effect of various detergent claims are your thing, too.

[lostu 0]

hi, alot of good points and like the last reply shops and traffic also sunday runs is it better just to put good normal unleaded in the S3 tank.as i at times i also use FORTE GAS petrol additive which i feel keeps things sweet ,or am i just wasting money ? lostu.

[deverett 9]

You mean I don't need to add the valve protector additive? I have a 1985 S3, just wanting to be clear on this because I'd love to ditch the additive.

In Sydney Shell V-Power has been unavailable since before Christmas. BP Ultimate is also out in my area. The only high octane fuel is Mobil 8000, which seems fine.

Dave Everett

[Rolf 28]

You mean I don't need to add the valve protector additive? I have a 1985 S3, just wanting to be clear on this because I'd love to ditch the additive.

In Sydney Shell V-Power has been unavailable since before Christmas. BP Ultimate is also out in my area. The only high octane fuel is Mobil 8000, which seems fine.

Dave Everett

Hi Dave,

had a discussion about the valve protector additive today with an Esprit specialist and he said post hc engines should use that, as the valve inserts were changed for the hc engine. If you not use it, check more frequently the valve clearance, so you are not burning the seats.

It is up to you, on the save side you are with the lead additive.

Regards to downunder,

Rolf

[AJay 1]

This question comes up every so often.

I have spoken to Lotus technical and was informed that all 910 engines are quite capable of running unleaded fuel, However they recommend Super unleaded or 98 ron or above in the non ECU controlled engines..

So if you are running on 98 ron then no additive is necessary. Obviously if you wish to play with the timing then theoretically you can gain more power by using an additive, but i have been warned that th 910 will produce good power right up to the point of detonation. So it is not really advisable......

Edited March 25, 2008 by USAndretti42 - Mod
Removed quote

[simonb 12]

Does anyone know for definite what an early 912 engine would run (as in a 1980 S2.2). Book says use 4 star 98 Octane, does it need valve additive to unleaded, or can I just run on super unleaded?

[USAndretti42 322]

You'll be good with the super-unleaded. The valve seats will cope.