The 'E' Type Forum

Can anyone advise what the best petrol is nowadays for an unmodified Series 1 - 4.2 Litre engine and should there be an additive many thanks

E5 95 octane , no additive needed

Thank you that was quick

christopher storey wrote: ↑

Tue Jul 12, 2022 1:20 pm

E5 95 octane , no additive needed

Is E5 95 octane? I thought all E5s are 97 or 99 - british octane that is. I normally put shell V Power 99 or Esso super in. E5 of course.

Super unleaded without doubt as they are 5% (E5) or less bio, Standard unleaded is 10% bio (E10).

At the last count, Esso Expensive whilst being branded as E5 on the pumps, is actually E0 in the UK except in Scotland and Devon and Cornwall, where it is E5.

kind regards
Marek

malcolm wrote: ↑

Tue Jul 12, 2022 1:52 pm

Is E5 95 octane? I thought all E5s are 97 or 99 - british octane that is. I normally put shell V Power 99 or Esso super in. E5 of course.

I think you are right, Malcolm. My mistake

This is geting more complicated by the minute is there a definitive answer?

Just filled up about 50L E5 £109

Bernie, yes, it was my mistake on octane rating which misled you. Any E5 ( that is with ethanol 5% or less - see the remarks about Esso above ) will do, and no additives are necessary

Bernie2015 wrote: ↑

Tue Jul 12, 2022 2:45 pm

This is geting more complicated by the minute is there a definitive answer?

No complication at all. Allowing for Christopher’s admitted typo his answer of E5 is correct. What is being pointed out is that it is variously 97-99 octane with the Esso version having no ethanol in most of the country as Marek says.
Avoid the E10.
Yes E5 is more expensive but it is what the engine was built for (the octane rating not the low or zero ethanol) and the car will run better and give you better fuel economy so the price difference is nullified.

Geoff

You must be realy clever

Or possibly just patronising

Bernie2015 wrote: ↑

Tue Jul 12, 2022 4:56 pm

Or possibly just patronising

Was that a joke of some nature? Didn't come across as one. Geoff was just trying to help by clarifying what we've all said.

Bernie...you had quite a few replies....and still wanted a "definitive" answer......Geoff,s reply was well detailed...how long have you had E types.....what fuel have you been useing?......Steve

Does the 3.8 need an additive? I’ve seen two answers to this question 1 No, 2 Yes
I’ve only put petrol in the car once as it’s only gone from where i bought it to the garage where we’re working on it, and the previous owner gave me a bottle of Redex and told me to stick some in. Thought it might be time to ask the experts

E5
No additive

E5
No additive

E5
No additive


There you go….that makes it 4-2….fairly definitive score I believe….( well it was in 1966…)…

Jonathan

I use Esso Synergy Supreme+ 99 in my 1963 3.8 FHC as well as in my other later cars. For me, this is the best fuel as in my area of Somerset, it should be ethanol free. Esso confirmed this and, from their website:

"Esso Synergy Supreme+ 99 contains zero ethanol, except (for logistics reasons) sites supplied from Scotland, North Wales, North England and Cornwall."

I see it's been mentioned that Devon (I believe you are there) is E5 for this fuel but, you could check with Esso. Note that the fuel is always marked E5 on the pump even if it's E0. As I think has already been mentioned, standard fuel is E10 in UK since last year (I think that's when the law came in).

This fuel is a good octane rating and should be zero ethanol. I'm not a great fan of ethanol for various reasons but if you don't use your car in the winter, it would be better to have this in your tank than fuel with ethanol. Your flexible tubing, seals and so on may have been upgraded but I'd still make the last couple of fills a non ethanol fuel before leaving the car for some months. For me, I only use about 1000 litres a year in the E-Type these days and the extra cost is not an issue but, it may be for some.

These are just opinions. I'm an aerospace engineer so not in the petrochemical field but for me, this is the closest easily available fuel to that which would suit the car best.

Good luck and enjoy your car.

Best, Chris

Bernie2015 wrote: ↑

Tue Jul 12, 2022 4:55 pm

You must be realy clever

Well, he can read! Consult your Owners Handbook for the definitive answer:

dlgis wrote: ↑

Tue Jul 12, 2022 6:24 pm

Does the 3.8 need an additive? I’ve seen two answers to this question 1 No, 2 Yes
I’ve only put petrol in the car once as it’s only gone from where i bought it to the garage where we’re working on it, and the previous owner gave me a bottle of Redex and told me to stick some in. Thought it might be time to ask the experts

There is no need for an additive - Jaguars are not like many cars which did not have hardened valve seats and therefore needed an additive when unleaded fuel became the norm. However, Redex will do no harm at all and is useful for minimising gum deposition in the fuel system , as well as reducing wear on a cold start