Good one Feral, couldn't have put it better myself.

I should apologise for being a smartass, but small quantities of methanol (CH3OH) and ethanol (C2H5OH) have the effect of lowering boiling point and extending the fuel, that is you can use a little less petroleum products.

The main downside is that both of these alcohols have a fairly lor calorific value--- they don't give as much energy per Kg as other fuels.

The other thing is that they can be manufactured from re-newable resources., which should excite the greenies amongst us.

So, when I sound off from time to time about ULP I'm only partly serious. Its still a sH!t fuel and causes more problems than it fixes.

Aunts Methyl and Ethyl.
Methyl is dangerous, a real poisonous bitch.
Ethyl is a sweetie

yeah please tell us

Ok what is CH30H and C2H50H????

Nick, you have raised a couple of important points.
(1) All IC fuels should have some sulphur (sulfur for Dave Gonzales) in them. If there is too much, you are wasting a prime feedstock for the manufacture of sulphuric acid (sulfuric for Dave etc.) If your fuel is crap, I don't know why as there is ample knowhow to make a halfway decent ULP.
(2) Small quantities of methanol in motor fuel are not a bad thing, we just seem to chuck a hissy fit whenever CH3OH is mentioned.
Talk to me about C2H5OH and it gets interesting.

the thing is in S.A our fuel is a crap quality, it has a high sulphur content and at altitude the fuel there has more alcohol in it to give those cars a extra boost.

we've been told to use 4 tanks unleaded to 1 tank leaded.

It doesn't matter where the engine was assembled. Alloy heads have seat inserts, as opposed to cast iron heads with integral seats. The inserts apparently are hardened. Cast iron heads may or may not have the seat area "treated".

In any case, we've been using unleaded in the US for about 15 years, and no problems even with cast iron heads (the fuel companies put additives in the fuel that work with any kind of valve seat).

In South Africa we have a Datsun/Nissan Factory.
Did we get the engines from Japan and just assebled them meaning I can also use unleaded due to it being manufactured in Japan?
We are going to only unleaded in 2006.
We can still use for now leaded.

bingo.

all datsun engines, bar the J series engines and previous (J13 and J15 are seen the the P310, P410 and 1500 utes) can run on ULP with no probs at all, except be nice to the world you live in and fit a catalytic convertor if you do.

from what i have been told japan never used leaded fuel or at least havn't used it in the time that they have exported cars so they are all unleaded, don't qoute me it's just what i have been told.