99 premium petrol

[Carol Anne]

Ive always filled my car with normal 4 star and ir runs fine, but I filled it recently with premium as it was all they had, and I was surprised to notice small but marked improvement in performance. Engine is 2.5 injection. Question is, if I keep on using this petrol will it cause damage to the engine, after it having done the past 65K miles on 4 star 95oct?

[Ethel]

Is yours an old classic car? It sees unlikely, being an injection, but cars haven't run on four star petrol for years.

[mr rusty]

I can think of one old injection engine straight off- Triumph's straight six in 2.5PI form: is it one of those?

I have a Vitesse with the 2 litre carb'd version, designed for 5 star and it certainly runs better with higher octane fuels, as I can run it close to Triumphs ignition advance settings rather than the massively retarded settings I have to use with an unleaded/booster mix.

[Carol Anne]

Sorry, I meant normal unleaded. Not a classic car just a 1998 rover 825

[rdv]

No it wont do it any harm in fact it will be slightly more efficient. The ECU will advance the ignition timing to take advantage of the higher octane fuel giving improved performance and economy

[Carol Anne]

thanks. I'll be using it from now on as it really does make a difference.

[Jay70]

Hi Carol,

Funny you should say this as I always ued to fill up with Morrisons standard unleaded but since the petrol incident I have been avoiding it. I went to Esso and they only had the premium 98 octane pumps working so I begrudgingly filled up with that but noticed I was getting about an extra 2 mpg from it so will have to work out wether its worth the extra.