Shell Optimax

[Dom]

Hi, anyone got an opinion on this new fuel that Shell are replacing Super Unleaded with. They claim it's got the highest octane rating in the UK, but are cagey in the actual details and just say it's greater than 98RON. It's also devoid of the British Standards rating.

Is it likely to be of any use in my mildly tweeked racing Fiesta or should I just stick with Super Unleaded?

[Jedder Cheese]

The octane level (RON) of super unleaded was (quietly) reduced recently by the oil companies from 98 to 97, so if this Optimax is 98+ RON then you could be able to get some performance benefits by tuning if your engine is knock-limited.

[Crash Test]

Optimax has been down here in Australia for a little while now, and from most sources, it seems to be better than any other pump form of unleaded. It has been adopted by just about all of the competitors racing in national competition.

[elephino]

For some cars...not all. For instance my car doesn't like it. While it runs smoother, the computer doesn't seem able to cope well enough and it runs way rich and therefore uses more fuel.

In Australia, standard unleaded is 91RON, Premium is 95RON but getting harder to find as there are so many 98RON fuels out now. Shell, Mobil and Caltex for instance.

[Crash Test]

I've heard of some farily serious gripes concerning the Caltex version of Optimax... It's cheaper, but much more nasty...

[elephino]

I haven't tried Caltex's one, but it doesn't seem to be any cheaper here.

[honest ron]

obviously the higher octane level.....the better speed available,..........but i dont quite know how it works...could somebody please help me here ?

[elephino]

I won't admit to knowing how it all works, but I do know that just having higher octane rating isn't the answer to more speed. It comes down to how well the fuel burns and how much of it burns. The problem with my car on the 98 octane fuel is that because of the higher octane, not all the fuel is burnt and the computer isn't able to compensate enough and therefore higher fuel consumption.

[THR]

see this months CCC for further info on optimax.

sounds like great stuff. cant wait for it!!

[Mox]

In Denmark theres no optimax. Instead there is "V-Power", but since the danish commercials for V-power is the same as the Optimax commercials I've seen - I suppose it's the same thing.

It's classified as 95RON Unleaded, and contains some additive that reduces(removes) build-up of stuff in the engine.

In a danish magazine they tested 2 similar cars - i believe it was Toyotas - both with some 80.000 miles on the clock.

The test proved, that not only did the V-Power guzzling car run better and get better mpg numbers, but also the amount of build-up around the valves and pistons were greatly reduced (almost totally removed) after 2000 miles. So it actually removed the stuff (damn - I can't remember the right word) and made the engine better than when the test started. Pretty impressive.

I bought my new car in June 2001, and it has never run on anything but V-Power. It feels quick, sounds good, no knocking or pinging, and it actually outperforms similar non-V-Power cars (I'm in a club, so we've tested it).

I cannot wouch for anything, and granted my tests are not very scientific, but I'm all in for this product !

Oh - and I have no relation to Shell or anything related to Shell.

/Mox