What MPG & RON.

[salty_monk]

I have a 1968 1098 2 door saloon, completely standard, running an electric fuel pump (is this standard??).

I believe that two final drives were also available, mine pulls strongly from 20mph in 3rd gear so assume it is the lower of the two???

I've been using Optimax with an additive (fbvh approved) that also includes an Octane boost (will be using valvemaster in future as it's cheaper & I like the measure...).

2 questions:

A. is it worth going to the expense of Optimax & an octane boost additive or is either or good enough (i.e. Optimax with standard valvemaster)?

B. What mpg should I be getting? I think the standard figure quoted is 38mpg.

Cheers,

Dan

[Kevin]

Yes the electric fuel pump is standard.
The 1098cc as standard has a 4.22 diff the lower one was only used in the commercial.
Although the `A` series is prone to valve recession only with some other engines any of the recommended aditives should be fine.
However I have a friend with a high mileage original engine now 140,000 + who decided a few years ago to just use unleaded as the engine was old and he would wait until it got bad and go for a full rebuild, well after 3 MOT`s abroad and 4 years motoring its still running fine, he does around 5,000 a year and its only the longer journeys that he does over 55mph which is when valve recession starts to have an effect, but as his engine already has a lead memory embedded into the head though many years of 4 star how much longer will it last is anyones guess, so it really boils down to the type and amount of motoring you do.
What Mpg depends on local driving conditions in my area Watford / M25 / M1 and quite heavy traffic I would be pleased to get that however I still get around 32 -35 so I am not complaining as a nine mile journey can take 35 - 55 minutes.