The 98/95 Ron Question- dare I ask it???

[Andy76]

I just trawled through various threads looking for info on this but didn't find what I was looking for. I do a fair bit of travelling some weeks and don't have time to seek out or detour past the nearest Shell or super unleaded friendly petrol station but if I need to carry octane booster so be it. Having had Subaru's in the past I am no stranger to this concept.

Specifically relating to a 63. The manual does say 98 Ron but 95 if nothing better, then goes on to say damage may occur blah blah blah. So a couple of questions

Has anyone actually had damage caused to a standard engine whilst running on 95? (either yourself or someone you directly know- not uncle jim bobs aunties step brothers cousin)

Are the 6 or 7 year old bottles of millers (still foil sealed) I just found in the garage likely to be in usable condition or will they have degraded as petrol does over time?

I would assume engine failures are rare and therefore failures attributed to lower Ron fuel is negligible as they are not mentioned all over every forum and that for general day to day cruising the 95 is perfectly acceptable as otherwise the manual would say only super/98 Ron.

Cheers
Andy

 

[jaymanek]

Your car will automatically adjust timing for 95 ron.

Try and stick to 98 or above where you can though.

Millers has an expiry date on it... It lasts for quite a while AFAIK.

 

[JamesRan]

I recently commented on another thread regarding fuel - it got rather heated!! A member of this forum decided to go on a rampage and criticise everyone's responses. Be warned!

But to answer your question, as said above I'd stick to 98 where you can.

 

[Mrhanky]

You know the answer already to this question and its be replied back to you already.

Stick with 98 min if you can, the odd half tank of 95 will be okay IMHO just not desirable on a long term basis.

 

[automaniaman]

I run mine on Tesco M 99, one the reasons being its availability...

 

[Mrhanky]

I run mine on Tesco M 99, one the reasons being its availability...

+1 and with the price reduction and points off its hard to find a reason why not.

 

[Andy76]

Thanks guys. Yes the answer is 98 as the manual says. It's trying to balance time efficiency/practicality against risk and I see the risk as fairly low. Jaymanek- thanks you confirmed what I had expected.

I don't really see Octane booster as practical cost wise but far cheaper than the potential consequences if MB take the same line as Subaru were alleged to in the early 2000's after a number of failures.

As it happens when I bought it the sales guys filled it with 95 and we more than happy for it to be driven as hard as I liked during the test drive.

Will just need to get into the habit of filling when passing shell stations again if I know it might be a few miles before I see another rather than what I had gotten used to with the diesel car of, fill it to the brim and run it til the light comes on! Some of the places I get to don't even have a Tesco!!

Thanks

 

[Parmzc63]

I wouldn't bother with 95 i think. i used 95 ron constantly for about a 1000 miles, one of the cylinders started misfiring so Back on Tesco 99 and is been fine since. I believe the fuel may have been the cause but cannot entirely prove.

 

[flango]

We had a customer who was a farmer and as tight as the ducks backsides he kept, he had a C63 that was run on supermarket 95 RON fuel from new, last time we saw it there was 84,000 miles on it and it still sounded sweet however on 95RON you will be about 60 - 75 BHP down on standard

Would I do it definitely not, if you own a c63 is another £4 a tank really going to break the bank ?

 

[-Ian]

We had a customer who was a farmer and as tight as the ducks backsides he kept, he had a C63 that was run on supermarket 95 RON fuel from new, last time we saw it there was 84,000 miles on it and it still sounded sweet however on 95RON you will be about 60 - 75 BHP down on standard

Would I do it definitely not, if you own a c63 is another £4 a tank really going to break the bank ?

60-75 bhp down on standard with 95 Ron. Really, and said in the nicest way do you have any proof to back that up ?

 

[flango]

60-75 bhp down on standard with 95 Ron. Really, and said in the nicest way do you have any proof to back that up ?

There's a thread on it somewhere with the dyno plots same dyno same day so definitely comparative not sure if it was on here or PH

Will try and find a link when I fire up my computer

 

[RJ C63]

Apparently they run the silver arrows fleet at the Mercedes Brooklands track on 95 ron so the driver we had told me...

 

[Howard]

Can't see why they would do that ?

MB fleet cars going against manufacturers advice ? In an environment where they want the cars to perform to the max ? Where no one is paying for the petrol anyway ?

Even my CLS500 handbook says to run it on 98.

 

[E270 Owner]

Apparently they run the silver arrows fleet at the Mercedes Brooklands track on 95 ron so the driver we had told me...

Can't see why they would do that ?

MB fleet cars going against manufacturers advice ? In an environment where they want the cars to perform to the max ? Where no one is paying for the petrol anyway ?

Even my CLS500 handbook says to run it on 98.

Errmm that was a joke I believe

 

[ChrisA]

Apparently they run the silver arrows fleet at the Mercedes Brooklands track on 95 ron so the driver we had told me...

April's fool come a few weeks early

 

[Howard]

Errmm that was a joke I believe

Ah I didn't realise

Tell your friend to use some smileys next time

 

[E270 Owner]

Ah I didn't realise

Tell your friend to use some smilies next time

Tell him yourself................I thought he was your mate

 

[c63chris]

My C63 took 95RON fine. As others have said, the car will adjust itself for the fuel. You'd be surprised how many do high octane versions so it's not as hard to find as you might think but if you can't 95 will be fine.

 

[Optimus prime]

Hi,

I run on 97 as this is a more standard super unleaded Ron (esso, bp, texaco, sainsburys etc) 98 and above is limited to shell & Tesco

 

[nico2014]

My C63 took 95RON fine. As others have said, the car will adjust itself for the fuel. You'd be surprised how many do high octane versions so it's not as hard to find as you might think but if you can't 95 will be fine.

You are sbbsolutely right Chris. My MB sales guy said the same thing to me but recommended once a month at least to fill with good fuel... Personnally, I have been using the 98 fuel mostly...