Hi people

I've got a MCS Jan 2011 Model. It says in the Manual that all MCS and MCS JCW should run on at least 98 RON (UK).

Is this the case?

I have noticed that when using Sainsburys Super Unleaded (97 RON) that it a bit more lathargic than with Shell Super (98 RON).

Is the engine going to have problems if I put in Shell 95 RON? :rolleyes:

Cheers
Carl

I use Tesco unlimited 99 RON and it is good value for money. But mine is an early R656 CS that states it required at least 95 RON.

Hi people

I've got a MCS Jan 2011 Model. It says in the Manual that all MCS and MCS JCW should run on at least 98 RON (UK).

Is this the case?

I have noticed that when using Sainsburys Super Unleaded (97 RON) that it a bit more lathargic than with Shell Super (98 RON).

Is the engine going to have problems if I put in Shell 95 RON? :rolleyes:

Cheers
Carl

Just follow the recommendations, and your engine will thank you for it, not only in the long run, less problematic combustion issues, but with the slight edge in performance, and believe it or not, marginal increase in MPG, when compared to 97 or 95 RON rated fuels, here in the UK.

Is the engine going to have problems if I put in Shell 95 RON? :rolleyes:

Cheers
Carl

Probably not, 'cause the engine management electronics will protect it.

But I can't understand why anyone would pay more to buy the peformance version of any car and then deliberately downgrade that by using cheap fuel that doesn't meet the maker's spec.

But I can't understand why anyone would pay more to buy the peformance version of any car and then deliberately downgrade that by using cheap fuel that doesn't meet the maker's spec.
My manual says RON95 for MCS and RON98 for JCW...

Take it from someone in the know! Use the recommended fuel. Failure to do so will create issues! Misfires and other running faults are common when the engine management detects poor fuel quality!

Cheers guys

I've been using Esso 97 RON for the last couple of tanks 139ppl - shell in my area is 144ppl. I'm going to stop using Sainsburys as issues above. Shame as its 136ppl!

Tesco is a bit out of the way for me, although I'll try it next time I pass one. :p

Performance is the bigger piece that will be lost with lower octane fuel. If you use a grade low enough, and the motor can't compensate, you run the risk of detonation and losing your motor.

This is more for forced induction motors. Naturally aspirated motors aren't affected as much unless they have an unusually high compression ratio.

It's not necessarily related to the quality of the fuel per se, rather the refining process that determines its grade.

If you use a grade low enough, and the motor can't compensate, you run the risk of detonation and losing your motor.
Every Mini engine ever built (Doh.... except diesels!) has a knock sensor so that there is no detonation risk and the engine will compensate for the octane level - so you lose performance/economy but not damage the engine.

Hey guys

My Cooper S (60 plate) states 91-98 RON on the fuel cap.....................does that mean its not advisable for me to use 99 RON fuel? Such as tesco Momentum99? I have spoken with a few people who say it won't do any harm at all, but its best to stick to the manufacturers guidelines of 91-98 RON.

So far ive only ever used the standard 95 RON fuel and im quite interested to see if the super fuel is any better in terms of MPG and performance etc.

Thanks in advance

Every Mini engine ever built (Doh.... except diesels!) has a knock sensor so that there is no detonation risk and the engine will compensate for the octane level - so you lose performance/economy but not damage the engine.

That and every other car (non-deisel)...I know.

I said if you use a low enough grade...never said what that is or that you can even get it.

And all you need is to overboost once (for those that are tuned or otherwise have aftermarket things going on) and you run that risk. Risk being the functional word. :wink: