Davehillbo
Member
About 30-35 on my Isuzu 2.8
gold rover
Well-Known Member
Sorry but just because it has a decent shell doesn't change the fact that it's just an isuzu
Or that even without the decent shell it's neither a p38 nor an L322
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gold rover
Well-Known Member
You wearing diver's boots?
Davehillbo
Member
Sorry but just because it has a decent shell doesn't change the fact that it's just an isuzu
Or that even without the decent shell it's neither a p38 nor an L322
Isuzu engines are the best!
chancehooper
New Member
I am getting about 14.7mpg on a 1995 4.6 hse but I just reset the ecu and sorting out a few electrical bugs and the tyre pressures should hopefully improve matters. It just bowled over to birmingham and back on under half a tank of fuel at motorway speeds but the short trips to the stables and back tend to pull the figure down again. Still, paid 1500 quid for it and it is rock solid so I can't complain in overall terms.
chancehooper
New Member
On a related note, my rangie is currently wearing 16 inch alloys with stock size tyres. Does anyone know if switching to a set of 18 inch tornados or similar would improve the mpg any? I am wondering if there is a rolling resistance issue in play? I will also redex the engine and change out the fluids again, but the next job is brake pads...
Will make no difference to MPG...rolling resistance will be exactly the same....
on 18's the P38 is a little wondery...have to get the tyre pressures spot on for a decent ride on 18's
Made no difference to me (maybe 20 miles more per tank) switching from 20's to 16's.
On my A3 TDI I gained 50 miles per tank switching from 18's to 16's.
Basically, smaller wheels are generally lighter and thinner, so less road resistance, and less weight so better fuel economy.
Got feck all to do with resistance....unless they are of narrower width...then there will be a small reduction in resistance...but if maintaining same width and similar tread pattern and depth, there will be no difference in rolling friction....
You could argue Polar and Mass moments of inertia and etc, but can't be arsed gooooooogle it!
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And my Masters was in Aeronautical and Aerospace Design Engineering so I don't need to goooooogle it either
But the tyre carcass tends to weigh more than the extra material required to make larger alloys. So it is twix and tweens. What makes most difference is correct tyre pressure. Changing wheel size was academic, I suspect you actually had the correct pressures for once.
