Super unleaded

[S500 Pete]

There is a thread running in the general chat section about the benefits/waste of money using super unleaded

Any of the tuning firms care to comment

 

[gizze]

Depends on the car, the German website says whether the cars are set up for 95 or 98ron, the UK website doesn't bother saying anymore for some reason.

It isn't some sort of marketing nonsense, it is either mapped for 98 or it isn't, if it is using 95 will retard the timing, lose you power and use more fuel than any financial saving.

This is the C63 on the left and the C200 on the right.......




Super-Plus is 98 and Super is 95ron.


Hard to find historical data though for cars no longer in production.


More often than not it is the engines that are pushed harder that need 98, the E200 vs E300 is a good example, the E300 is the same as the E200 but with 245hp instead of 184hp....

 

[00slk]

My only comment is that I run all my cars on that normal stuff 95??? Think it is that octane but anyway BP mainly and they all seem to go well, even my old 46 year old classic. However my 45 year old classic which is the same make and model will run on the same octane except I have to stall the car in gear every time I use it and switch off the ignition, it just runs on and on pre-igniting I tried retarding the cars timing which made it hard to start and lost half it performance
If I run it on 99 Momentum it is fine
The super unleaded will help its pre-igniting but not after a motorway drive, so Momentum for me

Does this help the debate?

 

[gizze]

Your SLK 55 is set up for 98ron, you can run it on 95 and it will retard the timing but it is not doing it much good.