Shell "V-Power" petrol

It can do, but in many cases it's more associated with a combination of imagination and it cleaning the injectors / donk for you.

I usually avoid paying the extra as it simply isn't worth it. I had a Laguna though that had rank rotten fuel consumption and I thought it couldn't hurt to give it a try for a tankful. Hey presto, 32.5mpg compared to 30mpg with standard unleaded. So I filled it again and got the same result. It was actually more economical to run it on Optimax - as it was called - than standard unleaded. So I did, until the bastard blew it's head gasket - again. So it was fixed and sold.

On the other hand, it's much better in my Triumph than regular unleaded, but that's because it's timed up for higher octane fuel. There's no noticable difference between V-Power and Tesco Super (99 octane, apparently), except the price and the less fishy smell of the tesco stuff!

Cheers,

Aye, my Triumph Vitesse runs better on it too - stops pinking. After the next fill up, I'll know whether it makes a difference to the Rover P6 TC too. It's currently on its first tank of ordinary petrol (in my ownership) and isn't running very well at all, but that could be due to the damp, misty mornings this week.

Hadn't noticed that!

Its unlikely to give you any more power,especially at low revs, but it certainly seems to smooth out my turbo boost a bit.

From

:"Using a fuel with a higher octane lets an engine run at a higher compression without having problems with knock. Actual compression in the combustion chamber is determined by the compression ratio as well as the amount of air restriction in the intake manifold (manifold vacuum) as well as the barometric pressure, which is a function of elevation and weather conditions.

Compression is directly related to power (see engine tuning), so engines that require higher octane usually deliver more power. Engine power is a function of the fuel as well as the engine design and is related to octane ratings of the fuel... power is limited by the maximum amount of fuel-air mixture that can be forced into the combustion chamber. At partial load, only a small fraction of the total available power is produced because the manifold is operating at pressures far below atmospheric. In this case, the octane requirement is far lower than what is available. It is only when the throttle is opened fully and the manifold pressure increases to atmospheric (or higher in the case of supercharged or turbocharged engines) that the full octane requirement is achieved.

Many high-performance engines are designed to operate with a high maximum compression and thus need a high quality (high energy) fuel usually associated with high octane numbers and thus demand high-octane premium gasoline.

The power output of an engine depends on the energy content of its fuel, and this bears no simple relationship to the octane rating. A common myth amongst petrol consumers is that adding a higher octane fuel to a vehicle's engine will increase its performance and/or lessen its fuel consumption; this is mostly false-engines perform best when using fuel with the octane rating they were designed for and any increase in performance by using a fuel with a different octane rating is minimal."

Z

One of the joys of running a carbed car is that I can just take off the=20 airfilter, pour a bottle of neat Redex down the carb, step back for a=20 minute and admire the mushroom cloud I've created and get the same=20 result. Far more fun.

--=20 Conor

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What, are you saying it makes a fishy smell?

My manky old Supra loved the higher spec fuels - it ran much smoother and was less hesitant at town speeds. Fuel consumption I didn't notice. It was either a bit better or a bit worse than *LOTS*.

Didn't seem to have any more oomph but it was nicer to drive with.

Makes a fairly noticable difference to my girlfriends Megane Coupe - couple of mpg over supermarket stuff. On mine it means I can run 5 degrees more advance and higher boost at the same knock levels :-) That has a negative effect on my fuel economy :-)

J