The AUSubaru.com.au Forums

Hi; my 89 L EA82 Carb motor has returned 9l/100k (25.4mpg) all town running none above 70k. Is this good, bad or ugly?

IMO this is good, almost to good. However is this just a one of or have you been getting these figures consistently over say a 2month period. I would have to be freeway running at 100km/h in my example to get that, and I dont have luxury (A/C P/S etc).

thats good fuel economy but as Fuji says are they long term or short term figures?

TOONGA

christ what car is that?
for 89 carby, i would be exceptional proud of myself, if i had managed to tune it to that efficiency. U sure u have enough fuel going in the enigne? hahaha
my 2000 outback was going about, 13l/100ks when i bought it (thanks to the guy that ripped me off) and after a basic rebuild (rings, bearings, heads, and seals) and a good valve clearance adjustment (which is a must after a head job) followed by a new MAP/IAT sensor, i have managed to get it down to 9l/100k avergae mix of 30km worht of freeway a day and about 50km worht of town driving a day.
so for a mechanical air fule ratio device liek urs, ur doing pretty well.
having said that, mine is a wagon what is urs?

Is good. No doubting it.

Forgot to mention; as mentioned in the whirring gearbox thread, my brain reached maturity 40 years ago. Perhaps a valium before you left home would improve economy. ;)Seriously though, yes, it is a one-off test,but a long time will pass before the next tankfull. I had a feeling it was too good. It is an L series wagon EA82, no steer and AC inoperative

age is no excuse for giving us figures like that. Are you testing the young folk, the older, the sleepy ones or what.

Did you get 9 litre per 100 km OR 25.4 miles per gallon?

100km is 62.5 miles - no arguement?
9 litres is one two gallon bucket - no arguement?

So... one bucket got you 62.5 miles?

half a bucket on average would do 31.25 miles ?

Think if you used 9 litres per 100km - you got 31.25 MPG

If you worked it out in miles and gallons first and got 24.5 MPG and then converted it backwards and used your own figures and head or pen and paper or calculator assisted

or did you use a US conversion method where US gallon is 4 litres, not 4.546 l in Oz.

My somewhat lighter Brumby with 3, 000km on its newly built engine .040" overbore, 20/60 Watson cam etc, did 609km from full std tank to dry, supposedly 55 litres.

609km = 393.92m
55l = 12.09 gallons

32.58 MPG, think tthat is 9.03 l / 100km

Now I'm confusilated. Distance travelled 274ks divide by 30.17 L =9.08. k's/l. Multiply 9.08 by 2.82(A constant used back in the dark ages; read 70's; when we were all trying to understand metric)= 25.6mpg. I tried your method but my head hurt. See if your way agrees. And as was pointed out on the forum it is only one tankfull

poprock1 wrote:Now I'm confusilated. Distance travelled 274ks divide by 30.17 L =9.08. k's/l. Multiply 9.08 by 2.82(A constant used back in the dark ages; read 70's; when we were all trying to understand metric)= 25.6mpg. I tried your method but my head hurt. See if your way agrees. And as was pointed out on the forum it is only one tankfull

You are correct at 9.08km/L

which equals 11.01L/100km

The constant is .6215 (miles to km) x 4.546 (gallons to litres) = 2.825

OK, it looks simple, maybe too simple I stuffed up, but if you want to see litres per hundred km and you stated 9 litres per 100km in first post, last you quoted kms to the litre.

I see 274 kms, so divide fuel litres use by 2.74 to get litres per hundred. That's it, sorry

Think I have finally given up converting these figs to MPG

And with one set of tyres I have 5% understate of odo so economy may be better than found at times, or worse

This is getting curiouser and curiouser, I forgot to mention that my speedo reads slow; 55kmh reading is a true 60. I would assume that the speedo drive cog is from a 3.9 or 4.11 diff instead of 3.7

Just not accurate is likely answer here. And did you know petrol expands as day warms up. Buy your fuel when it is most likely to be at its coolest, though in ground tanks not vary as much as say a depot filling tanker, tanker then on road for 300km during the warming up day and fuel expands, tanker delivers more than what was loaded, charges what was delivered

I also have a theory that the difference of accuracy of speed reading is not same as accuracy of odometer