Higher octane fuel

[Brek]

Originally Posted by SD1too

Alan, is that limited to 91 or 95 RON as MGR says, or could a higher octane be chosen?


How do you prove this claim without two identical cars and driving patterns?

Simon.

I can only compare it to when I put two tankfuls of 95 ron, the performance was impaired. I have decatted mine since and running V power since feb the mil light has not come on. I can only think that the engine is now running lean (as originally designed before Mercedes shafted us all with the cat) and the emissions are within acceptable range, I am getting noticeably better fuel economy.

[BigRuss]

The choices of fuel available depending on model/market are:

Leaded
Unleaded
90 Ron
95 Ron
Ethanol 22%

These are dependant on what market the car was built/destined for, the ZCS coding is different for whichever type of fuel is used, putting in leaded in a car built for a market where the use of a Cat is required would wreck it

The car will adapt to run on 98 Ron and as stated above there may be some power and a slight improvement in MPG

Russ

[JonQ]

Just read your post ,i have a ZT+190 that i bought from new and have only used optimax then V power and i have to say the car runs beautifully however my friends who have filled on ordinary unleaded have had issues with throttle bodies at about 40000 mls. my car is 10yrs old and still purring hope this answers your question regards

[bl52krz]

Originally Posted by MangoMan

Because different octane fuels burn at different rates/temperatures, so the ECU has to change the timing to achieve optimum performance.
It doesn't actually measure the octane, but the results of its use. This takes time.
I thought this quite obvious.

The hand book for the 75, page 98 states:- The RON value quoted above (95) is the MINIMUM requirement for the United Kingdom and most European markets. For optimum engine performance 98 RON unleaded petrol should be used..Hope this helps.

[wutang]

Originally Posted by bl52krz

The hand book for the 75, page 98 states:- The RON value quoted above (95) is the MINIMUM requirement for the United Kingdom and most European markets. For optimum engine performance 98 RON unleaded petrol should be used..Hope this helps.

that's odd in mine it says "use 95 ron, this can be safely exceeded if necessary."

must have changed at some point as its page 111 in mine.

Richard

[bl52krz]

Originally Posted by wutang

that's odd in mine it says "use 95 ron, this can be safely exceeded if necessary."

must have changed at some point as its page 111 in mine.

Richard

Inside the cover on the Handbook,there is a date of:- 6/2002 if that helps.

[rover54]

Originally Posted by BigRuss

The choices of fuel available depending on model/market are:

Leaded
Unleaded
90 Ron
95 Ron
Ethanol 22%

These are dependant on what market the car was built/destined for, the ZCS coding is different for whichever type of fuel is used, putting in leaded in a car built for a market where the use of a Cat is required would wreck it

The car will adapt to run on 98 Ron and as stated above there may be some power and a slight improvement in MPG

Russ

Is leaded petrol still available? I thought it was banned as lead in petrol is ejected unburnt and causes lead poisoning. The same situation with lead paint.

[rover54]

The only clinical way to see if there is a difference in performance between the different fuels is to do the same dyno test cycle with the same car with the various fuels, only then will the true situation be demonstrated. Also fuel consumption can be compared at various engine speeds and loads to give a true indication of fuel consumption. We had a dyno house doing back to back fuel tests 24 hrs a day, every day, but then our fleet of 6000 vehicles did 180million miles per year, so every fraction of a % saving added up to a lot of money. Anything else is subjective and bases on too many variables.

[SD1too]

Originally Posted by rover54

The only clinical way to see if there is a difference in performance between the different fuels is to do the same dyno test cycle with the same car with the various fuels, only then will the true situation be demonstrated. Anything else is subjective and based on too many variables.

Simon.

[carguy143]

I just run mine on Tesco Momentum all the time. I personally hate Tesco with a passion and the fuel is the only thing I buy from them as V power is still much more expensive and the only other garages local to me are Morrison's, Asda or Sainsburys which all don't sell super unleaded.