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Tesco 99 petrol verses the rest  
Tesco 99 petrol verses the rest - MikeTorque

What are your experiences of using Tesco 99 octane fuel ?

Does Tesco 99 produce noticably more power/torque when compared with 95 octane fuel ?

Does Tesco 99 produce greater fuel economy on a like for like driving basis compared with 95 octane ?

Have you noticed any difference in the colour of your vehicles engine oil when using Tesco 99 ? (i.e. does it stay cleaner for longer or not)

Does Tesco 99 help maintain engine performance over a period of time (1 year+) ?

How Tesco 99 compare with Shell V-power 99 ? (overall performance wise)

Edited by MikeTorque on 21/05/2010 at 18:25

Tags: fuel economy oil premium fuels v-power shell

Tesco 99 petrol verses the rest - Honestjohn

All I can say is today my average went up to 53.6mpg on Shell V-Power petrol. Not too shabby for a petrol engine. I think its because the engine fires better at low revs so you can use lower revs.

HJ

Tesco 99 petrol verses the rest - a900ss

Can't see it delivering much performance increase for a bog standard car but I had a tuned Saab Turbo 9-3 (about 235hp from 150hp standard) and it loved the stuff.

It was noticably faster and held onto turbo boost for much longer. Regular 95 would cause the engine to 'pink' and the car would automatically retard the ignition to prevent detonation. Tesco 99RON had no retardation and full power all the way.

BUT it was a tuned engine with a turbo, can't see the benefit for a bog standard 1.6 16V though...

Just my 2p worth

Tesco 99 petrol verses the rest - MikeTorque

HJ, have you tried a tankful of Tesco 99 and compared it to Shell V-power ?
Be interested to hear what your findings turn out to be.

Thorney Motorsport tested an Astra VXR with Tesco 95 and Tesco 99 petrol. They used 2 different cars and the results showed a 9% improvement in power and 10% improvement in fuel economy, that's pretty impressive.

a900ss, your findings support those of Thorney Motorsport. They tested using 2 standard tuned Astra VXR's and then retested using ECU upgrades, both sets of tests produced significant improvements in power and fuel economy.

Tesco 99 petrol verses the rest - cheddar

All I can say is today my average went up to 53.6mpg on Shell V-Power petrol. Not too shabby for a petrol engine. I think its because the engine fires better at low revs so you can use lower revs.

HJ

The Focus ST feels sharper on V-Power and Tesco 99 relative to normal 95.

As with most contemporay cars it is because the anti knock properties allow the ECU to optimise (advance) the ignition timing and adjust fuelling (and boost where applicable) accordingly.

Tesco 99 petrol verses the rest - unthrottled

I just don't buy the 'engine works better at low speeds' argument. For mild acceleration and certainly cruising, even a modest engine should be operating at a moderate BMEP and shouldn't require any spark retard from the ECU. I just don't see how the octane could be beneficial.

It be of course that the fuel's calorific value is slightly higher, or that the burn rate is faster. Fast burn is very important to efficiency. Sadly people get very attached to numbers (like Ocyane rating) because it's easy to make comparisons. but there's a hell of a lot more to fuel that facile numbers.

Tesco 99 petrol verses the rest - cheddar

or that the burn rate is faster. Fast burn is very important to efficiency.

Actually the burn rate is slower and more controlled, it is the slightly slower burn that provides the anti knock properties enabling the ignition to be more advanced. And the more controlled burn makes full use of the whole charge.

Tesco 99 petrol verses the rest - john farrar

I remember that Honda had problems with "high octane " petrol when used in the 1960's on their 5 cylinder 125's which were reving above 20,000rpm. The high octane (probably 110 ish) burnt too slowly and restrcted the revs, so they had to switch to lower octane fuel with a faster burn.

I believe that the octane rating is far too crude a measure to determine the quality of a fuel and there could be additional useful information to help choice(apart from the usual BS rating).

Perhaps the fuel providers wouldn't be so keen ?

Tesco 99 petrol verses the rest - SteveLee

On the other hand cars with actively managed closed-loop ignition timing might benefit at low revs, because at very light engine loads the fuelling might be very weak for better economy leading to detonation, which the knock sensors pick up and retard the timing - I suspect the difference will be tiny though.

A lot of normally aspirated Japs, Fords and Vauxhalls are actually optimised for 95 RON fuel so you're wasting your money with high octaine stuff. Turbo cars and most BMWs are optimised for 97+ octane fuel. Which is why it REALLY bugs me when the car mags routinely use (usually sponsored) super duper fuel (BP Ultimate, Shell Optimax etc) in their road tests - this favours BMW and will make their cars shine in terms of MPG and power/performance figures, both of which are reduced by running 95 RON fuel, where as your average Mondeo will produce the same performance and economy figures on "normal" juice or super brew.

Tesco 99 petrol verses the rest - MikeTorque

Well actually Vauxhall states in the Astra Owner manual that for 2.0 VXR they recommend 95 RON, they also state "Use of 95 RON fuel reduces power and torque. Slight increase in fuel consumption."

Tesco 99 petrol verses the rest - SteveLee

Well MikeTorque, the admission of a loss of power and fuel economy on 95RON shows their specified power output and fuel economy for that (turbo) model is on super juice. Not surprising as the majority of (high boost) turbo-charged cars are set up the same.

Tesco 99 petrol verses the rest - MikeTorque

Steve, the Vauxhall quoted power/torque figures for the Astra VXR of 240PS and 320NM are based on the use of 95 RON. If higher RON fuel is used then both power and torque are increased as well as a reduction in fuel consumption, see link below further details.

www.thorneymotorsport.co.uk/tuning/October_2008_Fu...l

I would be interested to hear about cars that also show similar power/torque increases and fuel consumption reduction when changing from 95 RON to a higher RON.

Tesco 99 petrol verses the rest - cheddar

I would be interested to hear about cars that also show similar power/torque increases and fuel consumption reduction when changing from 95 RON to a higher RON.

HJ has previous quoted Ford saying that the Focus ST produces 20 ish more BHP on V-Power relative to 95 ron. I can certainly feel a difference though I cant say that the economy is much difference.

While I understand how an ECU controlled engine can get more out of higher ron fuel to be frank that 25 - 32mpg difference along with more power is hard to believe.

Tesco 99 petrol verses the rest - john farrar

Apart from octane rating, does anyone know any other ingredient difference between Tesco 95 and 99?

Additionally, does anyone know the ingredient difference between the other premium products?

I'm not talking about advertising hype, but actual chemicals and their effect?

I would expect their concentrations to be secret, but I'm sure someone must have done chemical finger-printing on the various brews and published the data somewhere, though I've had no luck with the usual search engines. I probably need a specialist one(?)

Tesco 99 petrol verses the rest - MikeTorque

Extract below from the Greenergy web site :

An enhanced additive package;
To remove existing deposits and help the engine to run more smoothly, Tesco 99 Octane contains an enhanced additive package with twice the protective power of typical 95 octane fuel.

Full details :
www.greenergy.com/tesco_99_octane/product_benefits...l

Tesco 99 Octane Spec. Sheet :
www.greenergy.com/tesco_99_octane/Spec_Sheet_99_oc...f

Tesco 99 petrol verses the rest - xtrailman

Back in 2000 the A4 1.8T avant quattro i had was designed to run on 98 octane, that gave 180 bhp along with 171 lb/ft.

However it could be run with a slight power loss on 95, which i used 90% of the time, i could never find out what the power loss was, but the performance gain was only occasionally noticeable, no difference was evident with economy, 25mpg round town, 32mpg on the motorway.

If you have a VAG car its worth checking the hand book, just to see what octane is recommended.

I only used the 98 when towing, but at 5 pence per litre extra at the time, for me the cost was prohibitive.

It was quick on 95 anyway.

Tesco 99 petrol verses the rest - akr

Have tried Tesco 99 and V Power in my Mk6 Golf GTI and must say I can't tell any difference, either in power/torque or mpg.

I give it the odd tank of this stuff for its supposed "cleaning properties" but tend to stick to normal Shell the rest of the time. I just don't see how I can justify the higher price.

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