Thread: 3.5 Fuel economy

These are the common causes of 3.5 Hotwire EFI fuel consumption issues;


Faulty Thermostat, fit a new Genuine one .
Worn Camshaft
MAF faulty
Ignition timing retarded
Siezed distributor mechanical advance
Perforated distributor vac advance
Heavy right foot

If it is auto, slipping clutches or poorly adjusted kickdown cable.

Other than that, 400 to 450k per 80 litres is good for one of these.

JC

My 3.5 rangie 4spd auto does 14L / 100 on trips and gets as bad as 18L / 100 city cycle. If I floor it at every set of lights 22
I have had to replace a coolant sensor and thermostat (around 83deg)and keep it well tuned to get it this good as standard other than cam and exhast.
Some will claim better but with out head work and smarter ecu I think 14 to 16 L / 100 is OK.
Tony

If i was to get over 300km out of my tank i would be throwing a party I get about 270 out of my tank I think i have only ever got 300 out of it once.Its also a 3.5 V8 Disco and auto.Ive changed thermostat,coolant sensor,leads just put in a a brand new dizzy.Im leaning towards a worn camshaft in mine.What else could it be?

Originally Posted by SPROVER

If i was to get over 300km out of my tank i would be throwing a party I get about 270 out of my tank I think i have only ever got 300 out of it once.Its also a 3.5 V8 Disco and auto.Ive changed thermostat,coolant sensor,leads just put in a a brand new dizzy.Im leaning towards a worn camshaft in mine.What else could it be?

Big tyres and 3.54 diffs with a heavy foot

My brother has got a manual one,with about 300k on the clock,and it gets around 14-15l/100 most of the time.He does drive it pretty easy though.

Originally Posted by Rangier Rover

Big tyres and 3.54 diffs with a heavy foot

Even with my standard 16 inch rims and road tyres it was the same.I can drive it hard or easy and it makes no difference at all.Either way its shocking economy

I think a good 3.5 should be doing better that 20L/100 round town and better than 16L/100 on the highway.

This is all taken from my first 3.5 that got the above figures with 5" spring lift and 37" tyres with stock gearing and a rebuilt auto, all stock engine internals, had extractors and exhuast.

I persoanlly would be worried/annoyed if my rangie could not obtain 300ks to one tank!

p.s. I also should mentioned I find that I got upto 70k more from a tank of premium (95 ron), and have run premium in all my rangies since, adjusting the timing to suit.

Interesting commnets there. I found that the e10 stuff that we get here in QLD now might be a couple of sents cheaper but it doesn't return as good economy as std unleaded. premium does give the best economy I've found from experience but I'd be stuffed if I'm going to pay and extra 10 cents a litre for it .

3.5 economy, one word- CRAP. But I do drive my rangies pretty hard too so economy isn't in my forte. Plus you're hauling over 2 tonne lump of LR unladen as well, that doesn't help

Trav