Praise for optimax?

[tbloke99]

I've been reading a few posts lately and everyone seems to be going on about "filling up with a tank of optimax". Am I missing something here? I have just been using my normal unleaded but it seems that everyone else is using this optimax. Does it make much of a difference in running / performance, or is it one of these " claimed" things therefore everyone tries it.

[madasahatter]

I have an early 4.2 Cerbie, and the difference between unleaded and Optimax is chalk and cheese.

The car will start, and tickover far smoother in a morning.

A lot of the "jerkies" that occur between 2-krpm disappear.

The pinking of the engine below 3.5krpm on "large" amounts of throttle goes away

The car accelerates noticeably quicker (the ECU is mapped for 97/98 octane fuels, not 95).

Better all round really. Just a pity that in deepest darkest Warks it is a little difficult to find.

[joelk]

I use Optimax quite often, just in case my 4.5 Cerb isn't quite fast enough as it is...

I think it depends on driving conditions. For open roads / long journeys, I'd recommend it. It even seems to provide better mileage. Friends who do track days also say it delivers greater power.

For inner city short journeys, it's possibly fatser off at the lights, but goes through it a little faster than normal petrol.

If you belive the adverts, it's better for your engine too... apparently. Plus there's not a lot of difference in price anymore.

[olly]

We ran our late 97 4.2 on Optimax for about 1500 miles when it first came out. The difference ? F**k all ! The only difference we noticed was that it popped & banged less on Optimax than it does normally on Super.... (pops & bangs most on Sainsburys own super ?)

Oh, and for the record, early 4.2's should only be run on super (or optimax) anyway.... They weren't intended/designed to run on normal unleaded....


Editied to add - sorry if that seems harsh, we've just lost a sale on our house this afternoon & I'm gutted/pi55ed off....

>> Edited by olly on Tuesday 18th March 15:43

[tommomic]

Never drunk anything else (hic!), so can comment on difference - but the price difference is minimal, its what my cerbera has always had as its preferred tipple so why change, and its fun hunting down a garage that stocks it!!!!

........or you can use www.shellstation.biz

Cheers,
Tommo

[mike_e]

madasahatter said: I have an early 4.2 Cerbie, and the difference between unleaded and Optimax is chalk and cheese.

The car will start, and tickover far smoother in a morning.

A lot of the "jerkies" that occur between 2-krpm disappear.

The pinking of the engine below 3.5krpm on "large" amounts of throttle goes away

The car accelerates noticeably quicker (the ECU is mapped for 97/98 octane fuels, not 95).

Better all round really. Just a pity that in deepest darkest Warks it is a little difficult to find.

I think that just about sums it up. Optimax is the only 98RON fuel available on forecourts. It transformed my 4.5, it really does run so much smoother.

[Noodles 4.2]

Optimax is FAR cheaper than 97Ron and it is better fuel!

97ron at BP is 86.9 ppl in Bedford

Optimax is 81.9 - crazy.

Tony

[dannylt]

If optimax transformed your 4.5, there was something wrong in the first place most likely! Low rev/wide throttle pinking aside. The non Red Rose 4.5's are all tuned for 95. And like Olly said, only very early 4.2's are tuned for 97, in which case you MUST use 97 or cause serious damage.

danyn

[ro_butler]

Hmmmm,

My car has a sticker on it saying only use 98 ron fuel, but it is definitely a later engine as the dipstick is at the front. Maybe TVR had a job lot of stickers they wanted to use up

Rob.

[ches]

My car has a similar sticker near the filler cap but the hanbook says 95 ron. Tried them both, not the slightest difference.

[tbloke99]

So I take it that it only available at Shell stations. Do any other suppliers offer their "equivilent".
If I start filling with optimax now, will it cause any probs mixing it with what I already have in the tank?

>> Edited by tbloke99 on Wednesday 19th March 08:31

[olly]

No problems mixing at all - will just dilute whats already in there....

And yes, it's Shell Optimax, so only available from shell....

And there is no alternative (well, other garages sell Super (@ 97 RON), but Optimax is the only 98 RON petrol for sale anywhere).

[dannylt]

TVR use BP fuel for mapping, i.e. the Cerbera Red Rose engine mapping used 97 RON fuel. Optimax has a higher octane, but it won't make any difference. Of course, they all have different additives.

[Tam Lin]

The Optimax stuff seems to make more of a difference with turbocharging. In Sgirl's Griff, Optimax doesn't seem to make a difference, in the T5 Volvo the difference is pretty obvious vs "Super".

But for 1p difference (at my local Shell garage), you are buying a slightly higher detonation threshold due to the higher octane rating, which can only be beneficial?!

[RichB]

Tam Lin said: The Optimax stuff seems to make more of a difference with turbocharging. In Sgirl's Griff, Optimax doesn't seem to make a difference, in the T5 Volvo the difference is pretty obvious vs "Super".

Interesting, I'd never thought of putting it in my shopping car, but as I don;t "pay" for my petrol I may as well give it a try. Rich...

[TWIN T]

I couldn't believe the difference when I put Optimax in my 300zx twin turbo. There was none of the hesitation, Roughness, stuttering that was present before. Trouble is the nearest station is 15 miles!

The price is cheaper than the 95RON fuel here anyway (Melton Mowbray notoriously expensive for petrol).

Jst means I can go the back way to get fuel. :devil:

Ivan

>> Edited by TWIN T on Friday 21st March 15:10

[dannylt]

For cars with knock sensors, especially turbo's which will retard to preserve the engine, it should definitely make a difference.

But this is the Cerbera forum!

[Tam Lin]

dannylt said:
But this is the Cerbera forum!

Too right, and I can't wait to get my hands on a Cerbie!!!

[neilv]

dannylt said: For cars with knock sensors, especially turbo's which will retard to preserve the engine, it should definitely make a difference.

But this is the Cerbera forum!

Just to add my tupence worth, it wasn't around when I had my Cerbie, but never made a blind bit of difference in the Griff and the family hatchback actually seemed less responsive.

[trevorw]

I've heard from a friend that Optimax degrades within 3 weeks.
So by the time it is shipped to the Your local Petrol station, left in the stations tanks then put in you car it has possibly degraded down to 95 Ron anyway.

This is only what I have hear and i'm no expert by a Very Long shot.

PS make's no difference what so ever in my Focus.