Tescos Rocket Fuel !!!!

[Roobarb]

Bloody Hell, Tescos are going to sell RON 99 unleaded petrol in London and the SE by mid November. Apparently during tests users noted significant improvement in performance.

Who'd have thought it ?

[M@H]

Who's fuel is it..? Texaco.. BP.. ?

[Roobarb]

Greenergy are supplying it. Its a blended fuel which will reduce the amount of greenhouse gas crap your motor sticks out at present. So, not only is it 99RON, its better for the squirrels and birds to boot - and will prbobably be cheaper....

[TVR-NUT]

It's around here already. I've only used one tank full of it to date in my Corsa. Seemed to make it slightly quieter when idling. Not sure about a performance gain, but there may have been a little bit there?

Mark

[SXS]

Doesnt make sense? how can 99RON be more environmentally friendly??? Doesnt the resulting NoX go up as octane goes up?

[flinny]

It's round here too. But at 99.9 per ltr it can stay in the pump. My old girl isn't that keen on Shell optimax and I'm guessing this is essentially the same stuff.

[M@H]

Surely to your avererage motor designed for 95UL this is going to make basically sod all difference as the engine timing isn't changed..?

Matt.

[zippee]

M@H said:

Surely to your avererage motor designed for 95UL this is going to make basically sod all difference as the engine timing isn't changed..? Matt.

Might just be me but I do agree with Matt on this. I find no difference at all in performance when running say, Optimax compared with std Shell 95ron. Wasn't the std RV8 in the Chims originally mapped for 95 anyway?

[V8 Kieran]

I filled up on this the other day - think it was 95 or 97p. Didn't take much notice as I had to try 99RON!

It may be imagination/wishful thinking, but I swear the exhaust note was immediately louder/more aggressive, followed by more pops and bangs

I'm also sure the performance is up too although I've gone from 95RON (as my usual Sainsbury's "super" was only 97RON and didn't seem any different for the price so went back to "ordinaire"

[V8 Kieran]

I thought TVR RV8s were mapped for 98 but could cope with 95 - but maybe not?

[M@H]

V8 Kieran said:

I thought TVR RV8s were mapped for 98 but could cope with 95 - but maybe not?

They're set up for 97 Super Unleaded, hence it can be risky on some engines to use 95.. saying that a lot of them are just fine on 95 as zippee and others have experienced.

Cheers
Matt.

>> Edited by M@H on Monday 31st October 13:07

[SXS]

Timing is one thing, but if you increase the octane rating, basically the combustion in most road engines isnt really as efficient as it could be, so effectively the extra octane can spice up the combustion to some degree IMO... you'd normally notice better idling and some advantage in mid-range... the cerbie owners seem to notice a huge difference over regular super-unleaded with Optimax...

I always found BP Ultimate to be good, the Optimax just made more pops & bangs on mine which kind of makes you feel like theres more grunt, but I honestly couldnt notice any difference in performance, just an extra BIG bang now and agin...

[VYT]

Roobarb said:

Greenergy are supplying it. Its a blended fuel which will reduce the amount of greenhouse gas crap your motor sticks out at present. So, not only is it 99RON, its better for the squirrels and birds to boot - and will prbobably be cheaper....

Hmm, does that mean it contains 5 - 10% Ethanol? I notice here in Oz that the "green fuel" contains Ethanol and is usually higher octain. It is also cheaper....

[V8Smith]

Ive been running the Tesco 99RON super for a few months its being trialled at a few stores including my local Crawley) and its excellent, lots of pops and bangs, cant say I see much difference between it and Optimax, but others have said they can see the difference. My car runs very well on it which is all I care about and as I keep getting 5p off a litre its cheap too?

Mike

[M@H]

[oldfart]I'm clearly in the "old school" aren't I.. I always thought pops and bangs meant that your timing was allowing ignition later than it should be so that the exhaust valves were open, therefore was less efficient and meant less power.
[/oldfart]

Saying that I trust everyone who is experiencing this is just getting it on overrun ?

[Hoover.]

Tescos fuel can't grumble works well in my old girl....

For special occasions add some trackday octane booster for some serious flames

Yes my car needs a good tune up

[Roobarb]

Its using 5-10% Bioethanol. Which when burnt doesn't produce Co2. Its specifically aimed at high performance engines, and thus pitching itslef up against Optimax so I suppose it will contain all the engine cleaners Shell offer.
Pops and bangs only happen on the overrun and/or when you feather the throttle so that the engine is neither pulling or being pulled by the wheels whch sort of induces overrun. At no point should you have pops and bangs under accelaration. Higher RON = louder bangs.

[leadfootlydon]

My understanding is that the timing and fuel have to match.

Some cars have an ECU that is able to automatically vary the timing, or whatever, and thereby make proper use of whatever fuel is in the tank.

I used to have a Chevy V6 and, sure enough, the expensive 99RON fuel made the car run faster and smoother.

However, the ECU (Lucas 14CUX) in my Chimaera 500 does *not* automatically adjust and was mapped for cheapy 95RON fuel. In theory 99RON fuel would make no difference or be 'bad' for it. But, hey, it still makes 290+ BHP(engine), so I'm not too upset.

[dvs_dave]

As far as I know the Octane rating has no effect on the calorific output of the fuel. Octane is simply an additive to prevent pre-combustion.

As my understanding goes you will only get a performance alteration from running higher than standard octane fuels if your vehicle engine management system is equipped with knock sensors. If it is then the engine management will adjust the ignition timing accordingly for optimum performance. The knock sensors will tell the engine management that it can retard the ignition further than with lower octane ratings (hence the pops and bangs) because the fuel/air mix is more resilient to pre-combustion.

If you have a carb engine and you notice a performance gain then it's likely your engine was suffering from minor pre-combustion. The higher octane rating has simply delayed combustion until the correct point (i.e. when the spark plug fires) so operating more efficiently.

As far as I know

[deadslow]

I'm just totally shocked that so many of you fill your cherished sportscars with the cheap anaemic engineered by the lowest bidder supermarket petrol.