Optimax (again)

Peter Laborne · February 9, 2004, 23:27

Shell fuel = spending sh*t loads on a top-notch vindaloo at a top-notch curry house with 20 other members of MR2 ROC on a perfect sunny day in the middle of summer.

Tesco fuel = having a cheap own-brand microwave curry in a squat, then realising you don't have a microwave...or cutlery.

Hows that for a comparison?

Basically most supermarkets use well know suppliers of fuel, I work for Morrisons and we use Texaco - it's just rebranded. However the suppliers add different addatives for different garages. So a supplier delievering to their own chain will use the best addatives they can. When they deliever to a supermarket chain the addatives will not be as good.

This is why supermarket petrol - Tesco, Morrisons, Safeway, Sainsbury etc - is sooo much cheaper than the major garages - Shell, Texaco, Q8 etc. Sometimes by over 4p per litre.

Basically you pay for what you get. 76.9p for unleaded or 85.9p for Shell Optimax.

markiii · February 9, 2004, 23:54

Quote from: "heathstimpson"
Quote from: "markiii"not you rimagination.

the long term fuel map learns. When you surprise it it takes a while to re-adjust
Do you know how much difference there is between say a decent standard Shell fuel and Tescos s:?: :?: s:?:

not sure how t quantify it to be honest. Strange how my car always feels better running esso?

heathstimpson · February 10, 2004, 21:53

How do the big boys compare then s:?: :?: s:?: Shell, Esso, BP, Texaco, Total etc

markiii · February 10, 2004, 22:07

it's been said to me that every engine has it's own preferences and I'd tend to agree.

it's what feels best to you.

Personally

Esso
Shell
Texaco
BP

But thats based upon regular a i don't user super very pften.

Peter Laborne · February 11, 2004, 00:29

Quote from: "heathstimpson"How do the big boys compare then s:?: :?: s:?: Shell, Esso, BP, Texaco, Total etc

Gold = Shell
Silver = Esso and BP (BP's new fuel could push them up and knock Shell down)
Bronze = Q8 and Texaco

Then the rest.

markiii · February 11, 2004, 00:41

Q8?

Slacey · February 11, 2004, 08:21

Quote from: "markiii"Q8?

There were a couple of Q8 garages around when I lived in Birmingham, but I can't say I've seen a single one in Shropshire... evidently they aren't common down south either!

Anonymous · February 11, 2004, 17:06

This is an interesting topic. I use supermarket petrol in my Type R but every so often i tank up with optimax. The only things i've noticed are that with optimax the car seems to run a tad smoother but no faster.

Geoff. s:)

s:)

Anonymous · February 15, 2004, 10:06

Hi there everyone,

New user here, we only just collected our '00 MR2 Roadster yesterday and what a great little motor it is. s:lol: :lol: s:lol:

We've not had much of a chance to throw any fuel in it as yet, so I cannot give you an opinion on the use of Optimax in the MR2.

But when it comes to my GTO Twin Turbo, I use absolutely nothing else unless absolutely necessary. The lads over at the GTO owners club ( w www.gtouk.org w ) will tell you this also. The machine will run quite happily on normal unleaded and the ECU very quickly determines the change in octane, but I do notice a substantial drop in performance and decrease in MPG. s:(

s:( (and I don't like this, it's bad enough anyway)

However, it is a much older engine to that of the MR2, both physically and in design.

My general rule fuel preference is

Shell Optimax
BP Ultimate
Esso Super Unleaded
Super Unleaded from any other forecourt when the above are not available.

Justin

mph · February 15, 2004, 10:45

Unless you've modified the engine (ie ECU / compression), there is no benefit to running super unleaded: the stock ECU simply doesn't adjust to any noticable degree the timing values.

However, manufacturers tend to put their highest quality additives in their super, and this will have a bearing, not necessarily in the short term, but over a much longer period. Cleaner valves and less carbon build up with help with airflow.

Note, lower octane petrols invariably have higher calorific values and of course a faster flame-front - meaning they release more energy just at the right moment. Something to think about when if you're trying to get 100octane race fuel into your 1ZZ-FE..

Anonymous · February 15, 2004, 15:48

I wasn't actually suggesting that I would run Optimax in the Roadster (it's the other half motor anyway), just that it has made a considerable difference to the performance of the GTO, which is a 3.0 litre Twin Turbo charged beast.

The evidence is clear from datalogging that has been performed.

Quite how it affects the 1.8l engine found in the MR2.... I don't know.

Justin

mph · February 15, 2004, 15:50

Quite - it's when you get in the land of forced induction (or to a lesser degree, have cranked up the timing) is when octane is important.