Quote Originally Posted by debowen View Post
I certainly agree with Alpine on the cost benefit of sticking to the 91RON fuel, but when you try 98 RON you have to use a second tank as the computer takes about 1/2 tank to re-tune itself to the change. The 98 burns hotter and will clean out the carbon in the head, values and exhaust system. It adds about $5.00 to the cost of a tank (40lts) and is a bit cheaper than an injector cleaner. On that subject, I have tried a few brands and settled on FLASH LUBE. 250ml bottle is about $7.00 and I use 1/2 a bottle to treat injectors, cyl head etc. I do this every 20,000km in line with my auto trans fluid change and now stick to 91RON petrol.
98 doesn't burn hotter, it burns slower. That's why it can be used with more ignition advance. The additional advance compensates for the slower burning.

If you really want to clean deposits out, use E10. The ethanol keeps water from building up in your tank and dissolves deposits that will not dissolve in petrol.

It's exactly like the old bushman's trick of putting a cupful of metho in your tank to get rid of any water that might have got in there. Ethanol will mix with water and still burn. Petrol will not.

I have tried 91, 98, 95 and E10 in my Jazz with little discernable difference. My car has no taste buds so "nicer" isn't relevant. I use whatever get me the most km for the least $ and ignore the marketing BS put out by the oil companies.

"Put in 98 if you love your car" ?? FFS!