Silly MCS 98 or 95 ron petrol??

[Checkie_checkmate]

Well this may seem silly but....

I am wondering whether people think i would be best using 95 or 98 ron petrol, would the extra outlay be worth it?

I have a MCS with 500 miles on clock, standard bar JCW panel air filter, drive around 60-80 miles around town a week and 120 miles on the motorway at the weekend.

Your advice please

[mg1232]

Not silly at all!

I had wondered the same thing to be honest. I filled up with BP ultimate (97 RON) last time (as it was the only garage open with higher than 95 octane at the time!).

Fuel economy isn't great, even with motorway running (28.5 mpg according to the onboard computer). I have heard reasonable things about tesco and sainsburys high octane unleaded so I'm going to give that a go next. Oh, and I will alternate this with tankfulls of Shell optimax.

Just my thoughts and I'm sure others will recommend different.

The owners manual does say it can be run on 95RON though. It would be interesting to know if the performance figures were for 95RON or higher. Anyone know this?

[Checkie_checkmate]

Ah...the reason i ask is i got a average of 32.0 on a run of 60 miles in 6th at 70mph last week. I also got a average of 24-25mpg around town last week but just curious what other's thinks is best. That's on ASDA 95 ron too

Thanks for the reply though

[laura f]

BP or shell only, i'd never touch supermarket fuel with a barge pole we've found doing mostly town/urban driving that 97 ron doesn't make a vast amount of difference tbh

[mg1232]

It seems that that is about the average with the Cooper S really.

I'm wondering though if part of this is due to the fact that I have the climate control on all the time? I notice you have climate control too, and I know this must drink petrol, and probably drops fuel economy by several mpg.

To be honest, I knew I was going to take a massive hit with fuel economy when I bought the car, but that was something I was happy to accept in return for the handling. It did still shock me however, when I saw the onboard computer read 275 miles before refuelling, and that was as I left the petrol station! Gone are the days when it used to say 500 miles to go (admittedly a bigger tank)!

I agree with your commnents about supermarket petrol. Never use it myself!

[Themikanic]

Yeah it's funny about petrol. When I first bought my MCS, it was Optimax all the time. Then I read a post about benzine and it says how bad benzine is for the atmosphere etc. So then I thought about supermarket petrol and tried Caltex from my Safeway. My car runs the same, no problems & same fuel economy, and a bit easier on the pocket.
Mike in Australia.

[Ven0m]

I used to use Optimax in my MCS....now i've been converted to the darkside(Supermarket petrol)...Tescos 99 ron....feels more responsive and eager than before