What do you put in your C32?

Page may contain affiliate links. Please see terms for details.

AlanD

Active Member
Joined
Jan 22, 2011
Messages
609
Location
London
Car
CLS55 AMG IWC
I've seen a couple of threads talking about using super vs. plain unleaded, but apart from the odd "me too" from a C32 owner, no definitive comment on whether it makes much difference.

Is the ECU tuned for super or plain? Does it auto-sense? Does it a) feel better or b) get better economy from either one?

I had an Accord Type R once with an adjusting ECU, but it pinked like hell on plain and lost punch in the VTECH zone ... which really sucked driving around Ireland since super is almost impossible to find there now! ST220 doesn't seem to care a damn what's in it so I feed it plain.
 
All these modern cars will have knock sensors, and when you look at the book the figures are always for the 98ron version, however, something like a Merc will also run fine on 95ron too, it may not feel quite as responsive or give out quite the same power, but it will be more subtle than a VTech and many don't even notice.
 
Super. No noticeable power gain as its a supercharged and not turbo-charged engine. The gain comes from how long the fuel last. I get a days extra motoring with super (I use Shell mostly). I've done the maths and it works out at better value. Also a plus that most super fuel contain better cleaning agents for your engine.
 
Super. No noticeable power gain as its a supercharged and not turbo-charged engine. The gain comes from how long the fuel last. I get a days extra motoring with super (I use Shell mostly). I've done the maths and it works out at better value. Also a plus that most super fuel contain better cleaning agents for your engine.

Interesting - I've always struggled to measure economy as there's rarely such thing as a "standard week" of driving! I know when the missus does nowt but school runs it can drop to about 130 miles to a tank, and that 300 miles to a tank is pushing it for motorways, but anything in between is normal!
 
I'm trying the super vs normal tank range thing at the moment, I've managed 250 miles from full to empty on regular unleaded mix of 60% town driving and 40% motorway, going to fill up with super later and see what I manage with that.
It's the 55 engine not the 32 but I would have thought the results would be similar.
 
Normal 95ron cruse on the motorway . . ava - 21.1 mpg
Use 98ron and do the same route and speed. 23.9 mpg

Also more responsive and smoother.
:)
 
What does the manual/petrol cap say? I read a review that imlpied it was meant to run on 95ron (it might have meant to say that it *could* run on 95ron!).

Is it just me or is the price gap between 95 and 95ron getting bigger these days!? I know, percentage wise that goes without saying on the resulting amount of "p", but even beyond that! Maybe they figured they could just jam the prices up for that market as much as they liked without any complaints!
 
The higher Octane content the better, as the octane content in the fuel stops the air fuel mixture lighting off before the spark (detonation) therefore controlling the combustion process a lot more accurately. This leads to a much nicer, more consistent burn.

As said, most modern engines have knock sensors, so that if lower octane fuels are used the ECU can detect detonation and retard the ignition timing accordingly. However this does effect the efficiency of the burn, and reduces power.

Once you have used standard fuel the adaptions inside the ECU will take a while to adjust back to the original settings.

In short. I have always used Super in all of my cars. In my current Megane 225 will Tesco 99, it makes 264bhp and with shell 95 it makes 256bhp on our rolling road. Quite a big difference for another 5p or so a litre.
 
stops the air fuel mixture lighting off before the spark (detonation) .

stops the air fuel mixture lighting off before the spark (pre-ignition) .

stops the air fuel mixture lighting off after the spark (detonation) .(in the end gasses by the pressure wave rather than the advancing flame front)
 
ahh. Thank you for correcting me. It feels like a long time since i wrote my dissitation on this. :S
 
I only use V-Power in my C32 (and ML270). It only requires standard though.

As mentioned the knock-sensor allows it to advance ignition for more power - can't say I've notice it though.
 

Users who are viewing this thread

Back
Top Bottom