Thread: Fuel and oil for 2.25 petrol S2a

use any fuel that resembles unleaded that you like but depending on the engines condition you may need to run a valve saver oil or mix a touch in to lube the valves up. (thats part of what the lead in super used to do) if you retune the engine to run on the lower grade fuel you wont get any advantage out of the higher grade stuff and if you retune to suit the higher grade stuff if you go back to the low grade fuels you either have knocking or the requirement to retune BUT you can get a bit better performance from the engine.

use pretty much any oil from 5-40 up to a 30-70 depending on condition but I've almost exculsively run a 15/40wt oil in the engine and stock 80/90 in everything else.

The engine was designed to be run on a wide range of petrols, and was, in fact, sold in Canada without any precautions or problems during the period that only unleaded was available.

It will quite happily run on any petrol sold in Australia today, although for best results timing should be adjusted to suit the octane rating. Valve protectant is unnecessary unless you are almost exclusively driving at freeway speeds.

Unless compression ratio has been raised substantially there will be no benefit in using 98 octane - it is most likely 7:1 compression. Even if it is 8:1, there will be little benefit.

Oils - as Dave says, follow the grade recommended in the handbook, but remember that even the cheapest oil is vastly superior to the best available when the engine was designed.

John

Fantastic Black Night and Swaggie, thanks for your advice.