[Ross9]

Many words of wisdom from Ian there.

I always get a bit horrified when I hear of people putting "normal" petrol, ie 95 RON, in turbocharged cars etc, I think it's because the majority of my friends etc have turbo'd cars, and doing aall the upgrading and competetive use of our cars we do, it rubs off on our on the road driving as well, and it's pretty much necessary I guess to use the higher octane fuel. To be honest, when the Rover was standard I could have put 95 RON in it no problems, it was built in 1994, long before Optiplop and BP Ultimate etc, did you even get Super Unleaded in those days? (showing my youth, lol, I was 14 at the time), but I never ever did, it ran on Optimax since I got it, and BP Ultimate mostly now apart from a recent trip to the highlands wherte finding any 98 RON was a challenge and ESSO Super unleaded had to do. These days it needs higher octane fuel though, as a safety feature more than anything else, no knock sensor, and no ECU control of the boost apart from a 1 BAR boost cut that it never reaches.

I do have one friend who has a ridiculously fast car, thats in a very high state of tune, and during the week when he's just pootling to work and back, he will as Ian says, just put 95 RON in, personally I think this is madness seeing as the reason its so highyl tuned is that when the engine was rebuilt it was rebuilt with a fortune worth of goodies in it, it first died through detonation from using 95 RON and flooring it apparently. At the weekends and for 1/4 mile and track days, it gets its diet of 98 RON to allow all 350 horses to be used.

I'd still definately say that it's worth shelling out the extra few pennies all the time when filling up, the handbook for Jacqs T4 says 95 RON minimum, 98 RON recommended( or it might have been 97) either way, that tells me it should always have at least Super Unleaded in it, she was forced to put 95 RON supermakret petrol in once, and it was hesitant on acceleration for the first wee bit until the ECU knocked the timing back etc I assume. You wont catch me using anything less than 97 RON if I can help it, and BP Ultimate 98 ROn at all opperchancities, it showed better mpg on a run to Inverness up the A82 last weekend even with spirited driving, and is a better quality fuel if nothing else. As with optimax it cleans the valves etc as well (I know people who've had engines run only on Optimax for many miles, and you can see where the fuel has cleaned the valve's etc when they've opened it up) It's a compromise obviously for most people as no hamr will come of using 95 RON in most standard cars, the additional coss is more than outweighed by the benefits and peace of mind personally.