fuel econ for a 4.2 swb carby on petrol

[jo_shnz]

whats the fuel usuage for one of these,ive been told about 90ltrs will get 500km does this sound normal?

thanks guys

[Beastmavster]

That sounds exceedingly good.


350-400 is more likely, with a heavy right foot making closer to 300 possible.

[RN]

Depending on the state of the tune, 350 km is about all I can get running around on LPG. Impco dual fuel, about 90 litres. On a trip about 400 km.

93 Mav, manual, carby 150K

[Simo63]

That sounds exceedingly good.


350-400 is more likely, with a heavy right foot making closer to 300 possible.

I agree with Beastmaster. When we had our GQ 4.2 petrol, we couldn't get any more than 350 out of the tank and she was almost bone dry. We only had it for 6 weeks cos it used so much fuel and we unloaded it thinking there was something wrong with it. I believe the efi's get a bit better economy but I don't think that much better although some seem to calculate far better figures .. go figure? Different cars, different tune I guess.

[procompman]

yeah i get 4km/L out of mine on 33/12/15 the more lift and bigger tyres the less km

[rOd]

whats the fuel usuage for one of these,ive been told about 90ltrs will get 500km does this sound normal?

thanks guys

Would that be on petrol?

I doubt if those figures are on LPG.

I get around 23- 25 litres(LPG)/100km. (4.2 carb.)

Rod

[sideshow]

i got 5km per ltr when on petrol, Im now running straight gas and get about the same 400km out of 80ltrs running 35s. in a 90 carbied shorty.

pete

[MEX]

Sideshow & Rod,

I'm only getting 29ltrs/100km on gas and 25lts/100km on petrol and I think the car is properly tuned. I was wondering how your vehicles are setup compared to mine so I can make a true comparison.

I've got 32inch mongrels, 2inch sus, 1inch body, roof rack & its an auto.

Cheers MEX

[shortgq]

90 model carb maverick.... on 90L fuel,,,, get about 420-450km's mostly.... have had the carby overhauled which i think really helped...

[jo_shnz]

thanks alot guys

[chops]

I didn't think "fuel economy" and "4.2 carby" belonged in the same sentence

[rOd]

Sideshow & Rod,

I'm only getting 29ltrs/100km on gas and 25lts/100km on petrol and I think the car is properly tuned. I was wondering how your vehicles are setup compared to mine so I can make a true comparison.

I've got 32inch mongrels, 2inch sus, 1inch body, roof rack & its an auto.

Cheers MEX

I hardly consider my current fuel economy as good.

Ive had the carb rebuilt. = No improvement on economy

Replaced just about everything related to spark. = No improvement on
economy

Driving like a granny made a bee's dick of difference.

I only run 31" tyres.

[matthewK]

im running 31s 2 inch lifte on my 88 wagon 4.2l carby cleaning it up and all dose nothing for feul eco
i get 350-400 ks out of it and thats sitting on 90-100 between sydney and melbourne

[sideshow]

Sideshow & Rod,

I'm only getting 29ltrs/100km on gas and 25lts/100km on petrol and I think the car is properly tuned. I was wondering how your vehicles are setup compared to mine so I can make a true comparison.

I've got 32inch mongrels, 2inch sus, 1inch body, roof rack & its an auto.

Cheers MEX

I think it makes a difference running straight gas because it is tuned for gas only, not compromising between the 2. The gas has only been installed for about 8 months, pretty sure its just your usual impco setup.The shorty is running 4 inch springs 2 inch body and 35 mt/rs.
Pete

[chimpboy]

Big tyres make a big difference. My SWB got 14.5 litres/100km, petrol only, carbied, 29" cheese cutters.

I regret I never measured exactly how much worse it got on 32x11.5" muddies but I know it was worse.

I've also been told, but haven't confirmed through experience, that valve adjustment can be a weak spot for TB42s, poor valve adjustment->poor compression->poor performance/economy.

Might be worth considering, I don't know. It could explain why cleaning the carby etc doesn't make much difference, and yet there are still big differences between one car and the next.

Jason

[bogged]

Big tyres make a big difference. My SWB got 14.5 litres/100km, petrol only, carbied, 29" cheese cutters.

I regret I never measured exactly how much worse it got on 32x11.5" muddies but I know it was worse.

I've also been told, but haven't confirmed through experience, that valve adjustment can be a weak spot for TB42s, poor valve adjustment->poor compression->poor performance/economy.

Might be worth considering, I don't know. It could explain why cleaning the carby etc doesn't make much difference, and yet there are still big differences between one car and the next.

Jason

when it comes to fuel:
larger tires make a difference
wider tires make a difference
more agressive tires make a difference
more lift makes a difference.