Club 80-90 Forums

Hi all

Has anyone worked out or road tested what is better for fuel economy;

Retarding the timing (as recomended by Haynes) and running the slightly cheaper 95* unleaded

Or keeping the timing bang on & buying the more expensive 98* unleaded?

Wondering what would give the more MPG?
(P.S why are we still sticking with gallons)

I'm getting about 18mpg on super plus in my tin top 16" with solid lead, sorry, I mean MDF interior, or about 15mpg on gas.

There is an argument for that, but I doubt though:-

a) anyone has done the comparison;
b) anyone on here has the time or technical capacity to do it accurately and come out with a result that would stand up in court;
c) Could commision someone like Ricardo to do it, probably quote about £150,000 or so to do it comprehensively enough to be worth it;
d) if you advance to the correct setting and you find you can't pick-up 98 Octane, you'd be in trouble;
e) running on lpg, its possible to use the original timing, so I'm told, as it does indeed have a high enough Octane rating. Not sure if anyoen does though... so this might compensate wholly or partly for lost mpg on lpg (!)

gallons?

Why not - do your really want to have to invert the whole thing and talk about litres per 100 Km or some such daft construct.

If there's a prob converting from litres to gallons, just remember one number

0.22

It's reciprocal is 4.5454545454545454545454545454545

what would you rather remember?

Or for rough mental calcs use a factor of five and then take 10% off.

A gallon is a nice manageable sortof quantity anyway, petrol weighs about 8lbs, water just over ten and a cubic foot of water about 65 lbs (just 1% more than 2 slugs, the true imperial unit of mass). Litres and cubic metres - pah! Kilos? Well, I ask you, how can that compare to the noble British slug?

PS. HackBobSaw - Yea, I know

Keep the timing bang on and enjoy the extra oooomphf.

You knows you wants the power

If you want more mpg.. keep it stock and put a piece of wood under the accelerator...

15-18 around town/short/local and 20-25mpg on a run.. I think most would agree thats the norm on here!!

but its all subjective.. lots of weight etc, underinflated tyres, poor servicing etc etc.. makes a big difference..

if its running costs, go LPG.. even witht he drop in MPG it will be nearly half what it costs now!!

LPG has a lower calorific value thats why it gives less power/mpg (normally 5-10%) Timing can stay the same or even be advanced slightly, this will negate the slight loss, in most situations the loss is not noticeable.. if the system is set up well..

It's reciprocal is 4.5454545454545454545454545454545

from my brewing days for customs we used 4.54609 to convert to litres, its etched into my memory and will probably be forgotten long after spouse and offspring names are hard to recall.

Ah, that looks the correct one and means using .22 is .014% out, so someone values their pint highly! About 1.4 litres in 10,000

you find you can't pick-up 98 Octane, you'd be in trouble

hmmm this happened to me after Shell Island last summer, driving through darkest Wales was running out of gas n the liquid gold meter was in the red. Semi panic on

Lot of garages round where I live don't sell liquid gold either . .

Karl, Bet you wished you,d never asked!!! Rog;