fuel economy

[bruzer]

i just got my bj73 and i am getting only 15 mpg
air, oil, and fuel filter have all been change !
what should i check next

 

[crushers]

you did not mention the tire size or your driving habits. larger tires will change the fuel conomy, sometimes drasticly.
driving habits can really make a difference.
type of fuel you are running as well as any brake drag is another problem.
have you done a compression test? dirty injectors?

need more info...

 

[Entaran]

HZJ75 with 300's across for compression (well down, should be 525)
Weighbridge 2730 kg empty (6000lb)
33x12.5x15 BFG Muds
Average 16mpg(US measurement) with the 1HZ 4.2 diesel. ... around 15.3L/100km
Was far worse before a major service

Hope this helps.

 

[nikalex]

Good Day.
Being a geeky type of owner I have a spreadsheet for mileage on my BJ73. I have a 5 speed and stock 215/80-15 tires. My driving is unfortunately mostly rush hour Vancouver commuting. I get a solid 24.6 mpg (Canadian gallon) or 11.5 l / 100kms for those politically correct folk. This is a 3 month average. And yes - I work with a bunch of engineers.
Roman

 

[Entaran]

Forgot to mention that I also have a complete log of refills. I can tell you exactly which fuel station, the date, how many litres, how much it cost and the odo reading at the time.

 

[Wayne BJ73]

Hi there

Well

If I had fiques around 10-12lt per 100 I would be happy.

My BJ73 runs a 2H Diesel and I suspect its getting a little tired but returns figures 16-17lt per 100 (some times higher). I also run 33" tyres but didnt thing slighlty bigger tyres would make alot of difference?

Well my view only

All the best

Wayne

 

[pulag]

you guys are lucky. i have a 2LTE LJ78 with a 20lit/100kms. i have new injectors. had a compression test done, i forgot the reading but the diesel centre said it was ok within limits. thats the main reason i want to change the freakin engine. :C will it be worth it to have the fuel injection pump calibrated first?

 

[widewestcruiser]

Do tires make that much of a difference? My BJ74 uses on average 10.5 liters/100km with 33 inch tires and my hilux 2L diesel around 11.5km/100km.with 15/235
I would think the tire width, tread profile, and weight would effect fuel economy more then tire height.

 

[M John Galt]

Tire diameter makes a big difference, especialy if someone does not correct for the odometer error after changing tire sizes. In those cases the MPG is often calculated incorrectly.

 

[widewestcruiser]

Not really......here's a easy formula to calculate distance traveled;
actual speed= speedometer reading x new tire diameter divided by original tire diameter
example: 100 km X 32.7 inches divided by 27,8 inches = 117.6 km
I just add 15 % to my odmeter reading

 

[light_duty]

you guys are lucky. i have a 2LTE LJ78 with a 20lit/100kms. i have new injectors. had a compression test done, i forgot the reading but the diesel centre said it was ok within limits. thats the main reason i want to change the freakin engine. :C will it be worth it to have the fuel injection pump calibrated first?

No way in hell should you be getting 20l/100km on the 2L-TE. I get about 10.5 on the highway, maybe 12 around town.

Money says you've got drivetrain issues, brake drag, etc.

 

[pulag]

thanks for your reply light duty. i'm 99% sure. its 40liters for 200kms give or take a kilometer or two. i always fill up on the same time of the night, same pump, same vehicle position. i have 235/85/16 AT's (yokohama geolander)
how do i check my drive train? i dont have excessive brake wear, the auto tranny shifts a little late to 3rd i have to get to 2400rpm for it to engage. (its a 3speed auto i think?) my first auto tranny. any suggestions guys?

 

[Martin White]

All the calculations are great, but you should try to get a GPS calibration of your odometer to confirm your base numbers are accurate. You may be off more than you think. That of course assumes you can get an accurate GPS to work from. Some are more accurate than others.

 

[David*BJ70]

This thread is not pertinent.

All you guys compare the fuel/km on a base of different engine ! 3B, 13B, 2H, 2LTE, 1HZ...

 

[David*BJ70]

Good thread about 3B fuel economy : https://forum.ih8mud.com/showthread.php?t=29920

 

[sandcruiser]

2H with 31" tires, HJ60. Mostly slow driving around town and dirt roads I rarely get under 11l/100Km, but usually do better than 13.

For example.

 

[Glenn-BJ74]

BJ74 Mileage

Vehicle is a 1989 BJ74 with 13BT engine, stock boost, with 12.5X33/15 Truxus Radials on 8" wide rims, PTO winch, Old Man Emu lift - all things that affect mileage. Conservative driving style.

GPS mileage corrected at 15%

Based on an average of 2,536 miles (July 2006 to December 2006) of about 70/30 town/ highway I got 25.9 mpg (imperial gallons), with a range of 23.1 to 28.5 mpg per tank.

 

[UpsideDown]

1987 HJ61 - just drove 530 kms (measured by GPS) 31x10.5x15 tires.

Averaged 100km/hr for that time... going from Vernon to Vancouver via Kamloops. On the Coca-Cola highway, I was going like 100 to 125 km/hr to get my average up to that 100 figure.

Total fuel burned: 58 litres.

Mileage 10.9 L / 100km

Needless to say, I am happy with that And it was 5th gear all the way on the Coq with power to pass on the hills.

 

[Axel Von Gardan]

Mine -90 LJ70 with 2LT2 takes about 11.5L/100km with 33x12.5x15 mudterrains and 3" lift, with boggers it takes little more