Millbrook Report: Tesco petrol vs Premium

EdGasket

Well isn't it pretty meaningless to say 'a competitors' this and that? The competitor's petrol might be Asda's for all we know.

BeenThroughItAll

A report published in 2012 backs up the fact that, basically, there's no really meaningful difference between Tesco's fuel and someone else's fuel.


Hold the front page, I've said that many times on this forum, based on actually working with fuel companies and distributors.

owen_money

I do 30k miles per year and get Tesco points, car still works

AdrianC

motorguy wrote: »

You're drastically missing the point of the Tesco 99RON fuel.

Some cars have to run on higher RON rated fuel OR run better on it when they do.

OR more accurately - cars requiring higher RON rated fuels wont run as efficiently on 95RON rated fuel.

No, that's LESS accurate.
If a car requires higher-octane fuel, it won't adjust down to 95, and will suffer definite problems - pinking, most likely.

These cars are usually performance cars. For example our A45 requires higher RON rated fuel, as does my sons Clio RS200, as does my Boxster, as did our 370Z GT, to name but a few off the top of my head.

If any of those cars were run on 95RON fuel, the cars will adjust but you will loose a percentage of your power and some fuel efficiency.

So they don't require higher octane... They are mapped for 95, as well as higher octane, and will choose the appropriate settings - ignition timing, most commonly - for either fuel.

There are very few unleaded-era cars that require higher than 95. Mostly, they're Japanese-spec imports, some of which require up to 100, and won't adjust to compensate for lower.

Let's face it - if you're driving something as fast as an A45 hard enough for the change in mapping to be anything more than psychological, then you're driving FAR too fast for public roads. And I very much doubt that any economy increase leads to lower cost per mile, given the price margin between the fuels.

Using a 98RON or 99RON fuel in an engine that has been designed to run on 95RON fuel wont make it any more powerful nor will it make it any more efficient.

That's correct.

DoaM

BeenThroughItAll wrote: »

Hold the front page, I've said that many times on this forum, based on actually working with fuel companies and distributors.

Same here. I've been to the road terminal at Grangemouth and seen the various different companies' tankers lining up to fill up from the same loading tank. Perhaps some of them put an additive pack inline with the loading arm, but the base fuel is exactly the same.

Apodemus

motorguy wrote: »

For example our A45...

Lol! Had to look that up, my mind was on 1950s Austins!

debtdebt

I run an Audi A8 with the 3.0 TFSI petrol engine. I probably operate it within 25% of it's true capabilities. Always stuck supermarket fuel in and never had a problem.

motorguy

AdrianC wrote: »

No, that's LESS accurate.
If a car requires higher-octane fuel, it won't adjust down to 95, and will suffer definite problems - pinking, most likely.

No, thats incorrect.

The car gets its promoted BHP based on running on 98RON.

The sub text - which if you want to nit pick which you usually do - is the car requires 98RON (to make its promoted BHP figure) .

The car adjusts the timing to prevent knocking / pinking. So you lose power.

AdrianC wrote: »

So they don't require higher octane... They are mapped for 95, as well as higher octane, and will choose the appropriate settings - ignition timing, most commonly - for either fuel.

Oh look - nit picking. To get the promoted BHP that you paid for when you bought the car, you are required to run it on 98RON.

AdrianC wrote: »

Let's face it - if you're driving something as fast as an A45 hard enough for the change in mapping to be anything more than psychological, then you're driving FAR too fast for public roads. And I very much doubt that any economy increase leads to lower cost per mile, given the price margin between the fuels.

Agreed - as its a ridiculously quick car, but running them on 95RON is known to make them less responsive, and significantly harder on fuel. However why have the car adjust its ignition timing and hence power down to compensate for running it on the "wrong" fuel? No point in paying for 376BHP and not having access to them.

It requires 98RON to get the promoted 376BHP, so it gets it. We dont begrudge it a penny of its fuelling cost.

Joe_Horner

owen_money wrote: »

I do 30k miles per year and get Tesco points, car still works

Ahh, but have you checked your tyres recently?

motorguy

Apodemus wrote: »

Lol! Had to look that up, my mind was on 1950s Austins!

And ironically, you've probably seen them on the road but never looked twice at one - which is the way we like it....