Fuel

[Harold W]

Hi all
 
Is someone able to advise me as to what amount of 100 + racing fuel you need to add to 4 L, or a gal , of unleaded fuel to boast it up to a worthwhile mix ? Out here in N Z we get 91 or 96 oct but both are a problem or compromise with old motors.

[Alec]

Hello Harold,
I\'m surprised that your 96 octane fuel causes a problem, as that\'s about the best we have in the UK now. I personally run my 2.5 P.I. on \'cooking unleaded\' (There is a premium unleaded with higher octane) although I do use a fuel additive which also has an octane booster, with my timing set to standard as Triumph list for leaded fuel.
I don\'t know the answer you are looking for but suggest that you speak to the technical department of a fuel producer.
regards,
Alec<edited><editID>Quasi</editID><editDate>38195.372974537</editDate></edited>

[Harold W]

Thanks Alec&nbsp; The quality of fuel here is not good and can vary from one batch to another. We did have an independant supplier who was importing fuel and the quality of it was much improved on the local 4 big companies but they were bought out by one of the 4 and that was that.&nbsp;

[Clifford Pope]

If it varies from batch to batch you are not going to be able to do a very scientific mix, unless you have something for measuring the octane rating.
<br>My inspired guess would be that if you mix 1 part of 96 with 1 part of 100, you get something rated 98. Isn\'t that what the Octane Rating means - the equivalent % of pure Octane that would produce the same knock resistance as the sample tested?
<br>I use an additive (Millers VSP over here) to give valve seat protection and octane boost.