The benefits of high-octane unleaded petrol outweigh the extra cost of the fuel, expert tests have concluded.
Thorney Motorsport compared two identical Vauxhall Astra VXRs on the same routes over a four-month period.
Standard Tesco unleaded was used in one, Tesco's 99 Octane brand in the other.
The car running 99 Octane averaged 25mpg during the tests, while the lower-octane fuelled car returned 22mpg. That's an overall improvement of 14 per cent.
Daily dyno tests also revealed that the VXR running on 99 Octane produced 252bhp on average, compared with standard fuelled car's 235bhp.
Thorney Motorsport concludes that it's worth paying extra for the Tesco 99 Octane fuel, because you can go further on a tank.
However, high-octane unleaded is known to have a greater effect on heavily tuned and turbocharged cars like the VXR than it does on lower-spec, naturally aspirated models.
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Re: High octane equals better mpg
As a Z4M owner, yes I am an economical driver. I didn't by a high performance vehicle just to be a cock, and while the performance and handling is everything I would expect it to be, I need it to return a certain level of economy too when, for example, I go on long runs (London to Menton, and back six times per year, around 800miles each way), using fuel like V-Power makes all the difference, as well as driving sensibly, having the car nicely set up etc. One doesn't need to nulify the other.
Re: High octane equals better mpg
So your an economical driver are you?, if you were you'd not be driving a high performance vehicle, you did'nt buy it to see how many miles per gallon you got , you bought it for its performance/ handling ect.Now i don't drive an eco car either (530i M-Sport,30mpg), but thats mixed driving, longer drives it does 34mpg on ordinary unleaded, i don' see the point in using higher octane fuel for such a small increase and now that petrol is down to under 89p per litre who needs high octane fuel now anyway.The best way to eek out fuel is be a bit less lead footed, change gear a the correct times, check yourtyre pressures are correct they have a big effect on mpg, these and a few you can come up with yourself will still give you what you want from your car and put a smile on your face when you want to be a bit of a hooligan......merry christmas to you all !
Re: High octane equals better mpg
I've got a Subaru WRX PPP, 03 plate. I've run with normal petrol and with Optimax, compared results from both. Gave each a few tanks to bed in before monitoring over a few fill ups what the MPG was during a normal week's worth of driving.
Optimax gave better MPG - 26 vs 22.
Optimax has better torque at lower revs.
Optimax felt more powerful at higher revs too.
Optimax has now been replaced with V-Power, which gives similar results.
Tesco 99 doesn't have the same torque at lower revs, and while I didn't do such an extensive test it didn't seem to give the same MPG as the Shell product either. Remember that Tesco 99 has a high bio-fuel content, so it's "calorific" value is lower. You get less bang for your buck! As for normal Super Unleaded at 97 RON, car runs better than 95 RON but not by much. The car is just so much smoother and refined when running on the Shell product. Plus, the extra MPG more than covered the extra cost.
I don't work for Shell, and these are just my own observations. Your experience may be different.