G'day guys and gals just wondering what fuels people use. I am using shell optimax in the new 1600 and it works a treat but was wondering if i should be using some kind of additive as well?

i'v heard that post 67 engines had hardended seals, maning u didnt need any additives.. but i do not know how true this is..

NITROS!!!! lol

yes that is true and optimax is what I use aswell but I also use the additive Valvemaster it is a upper valve lubricant this mey not be a neccesaty but its just a bit of peace of mind .

did i say AVGAS!!! lol try some octane booster...

liquid hydrogen

This topic has been done to death. Please do a search for the full arguments.
Optimax is a waste of money as airpumpers cannot take advantage of its claimed benefits ie higher density. Some people think it fouls plugs, leaves deposits etc. other people think it's great. The higher octane rating will not help if you are running standard compression ratio.

Use a brand name leaded petrol and all will be good. All but the earliest VW motors have hardened valve seats so even regular unleadd is OK.

If you want use LRP, some people claim it will cause problems like plug fouling but I've used it for over five years and have never had any discernible problems.
You will not get a definitive answer.
Use petrol, not diesel, not LPG, this is about as definite an answer as you will get.

Many years ago I had a friend fill his Baja Cal look cross with diesel due to the petrol station we filled up at on the way home from Bug Jam having different colour pumps from every other petrol station in the UK (Red was normally leaded and black was normally diesel)... Makes a nice big cloud of smoke I can tell you. Also took us all quite a while (a week) to work out what had gone wrong with his motor :thumb

For a stock standard 1600 use lrp (cheap and simple, but has a bad rep for fouling etc.)

More concerned about your fuel, use straight unleaded, but with FLASHLUBE (upper cylinder lubricant and protector against valve seat recession) added every fill. Single carb engines can easily make use of the flashlube kit which hooks up and meters the flashlube automatically.

Higher compression motors should use any high octane fuel WITH VALVE PROTECTION added (like flashlube) eg Mobil synergy 8000, or BP Ultimate if you can pick and choose, otherwise Shell optimax is easy to get hold of everywhere, although carburettor rebuilders complain that the cleaning agents in it can corrode bits and pieces. just use it every fifth tank for a good clean maybe.

I've experimented with all three high octane (98+) fuels and found them the same in mileage and seat of pants perfromance, so have no real preference. Caltex is bringing out a new high octane fuel to replace vortex since it's not a true premium fuel... only 95 or something. I tend to steer clear of caltex for reasons I'm no legally longer allowed to state.