Petrol - Supermarket vs. Branded

tomstickland

Arghh, Redex, horrible stuff. I was thinking more along the lines of Millers Octane boost.
Say there's a 4p per litre difference between supermarket and a big name, then that's roughly £1.60 on a 10 gallon tank.
OK, Halfrauds want £5 for STP power boost (http://www.halfords.com/webapp/wcs/stores/servlet/ProductDisplay?storeId=10001&langId=-1&catalogId=10151&productId=192987&categoryId=58759)
The STP website says you have to pour entire bottle into a tank of fuel (http://www.stp.com/fuel_oct_boost.html)
So it's more expensive than buying more expensive fuel.
Well, the break even point is when the extra cost of fuel reaches £5.
So that's be around 11p per litre difference for a 10 gallong tank.

Crabman

I did 130 miles back home yesterday. The journey away I filled up with Tesco fuel (95.5p). For the return journey I filled up with Shell which was only 91.9p :T and almost instantly I noticed a difference in drive quality. The engine stopped groaning and when I hit the gas, the car took off.

Before you ask, I did not use optimax - I used the regular (or premium as they call it) unleaded. Much cheaper in Wales :T

Anyone know why the drive would be different?

Oh and also I've done 150 miles as of 5 mins ago and the fuel gauge is still half way between three quarters and full. Very strange but welcome :T

Dave80s

The EVO mag test was done using a new M5 and a new Golf Gti (200bhp turbo model). In general the higher the octane fuel the more power they got out of the cars. Although there were some suprising results like a fill up of regular stuff at an Asda store which provided a big bhp increase.
They said the fresher the fuel the better it is, so choose a busy garage.
Evo once ran 2 engines for 50,000 miles (I think), one on regular 95 (can't remember which brand) and one on Optimax. When they took the head off the engine the difference was clear. So it does clean your engine, regardless of what else it does. For this reason the Evo jouno said he would only use Optimax in his cars.
p.s. Tesco Super UL (99 ron) is supplied by Greenergy and has a 5% bioethanol mix.

slates

I'm the first one to admit i'm not very cars and engine savvy. But when i did my family duty of visiting them 240 miles away, i noticed the difference after using fuel bought from BP as well as doing the journey home i did some more miles travelling around down there and i didnt have to fill the car up till i did the journey home, normally when i have filled up at the supermarket i have had to fill up a lot sooner..so for me i would have to agree that BP/ESSO are far more superior.

tomstickland

I'm now keeping a spreadsheet of stats for each tank of fuel. Within a few months I'll have enough data to demonstrate any difference in fuel supplier.

gazhawkins

In for a penny, in for a pound.... I run a 7 year old Toyota Corolla 1.6 petrol - get 36mpg on Sainsburys or BP ordinary unleaded 95 week in week out - no difference in performance. Perhaps unsurprising, as some posts suggest BP supply Sainsburys with fuel.

I'll try Total next week.

Perhaps for most MSE fans, it comes down to the price, rewards on offer and the cashback on the credit cards used - and good luck to you.

northern_munky

I think this works for some and not for others (or it could all be in the mind ), I have heard people who say their cars don't run well on Tescos and run better on Shell. I used to only fill mine with Esso then when Tesco opened near me I started using that, never noticed an ounce of difference in performance of economy and thats with quite a high performance engine.

Crabman

Heard that Morrisons is now 89.9p/litre unleaded (95 octane) all over the country :T

bunking_off

Where I live, Shell costs the same as Morrisons and Tescos...so no-brainer to go for Shell.

The real question, then, is whether to go for Shell standard or V-Power (as it happens, neither Tesco or Morrisons sell 98/99 RON locally). Price differential is 6p/litre (quite a % when you factor in how much of the price is actually for the petrol versus the tax). For me, the factors are;

- the differential is reduced by having a Shell card which gives greater benefits when buying V-Power (or Optimax as was).

- I drive a car with a 4.2 supercharged V8 (yes, very moneysavingexpert, but there's no point in saving money on other things if one doesn't have an indulgence...). I've tried various fuels - through necessity/availability rather than choice. On supermarket stuff it drives like a dog, on Shell normal it drives ok but put your foot down and the blistering performance just isn't there. Only 98/99 RON stuff cuts the mustard...of course on a 1.2 Corsa, this may not be so material.

- manufacturer of my existing car are happy for it to be run on either 95 or 98. However, manufacturer on my (lower power) last car were more explicit - run it on 95 if you must, but you've just laid out a fortune on a performance car so give it the fuel it deserves.

- assuming no off-setting increase in mpg (and, to be honest, I don't buy the argument that Shell gives materially better mpg than anything else), at 15k miles/yr, using V-Plus costs an extra £150/yr. My car's worth £25-30k - think that's a worthwhile premium to protect my favorite toy...

tomstickland

Yes, the marginal improvement using Vpower (see the Ride mag testing where Optimax gave 2-3% more power) is probably worth it if you have a high power engine. I used to use Opticrap mainly when I had a tuned up engine with quite high compression ratio and drove it hard.

For most people then V power doesn't really offer anything worth having. I don't bother with it in my 135BHP old BMW. I mean, I might gain another 2BHP on a good day, but I'm not really interested.

My testing of supermarket vs big name hasn't got enough data yet, but I'm starting to think that I'm going to get similar results with both types.