I've checked my truck using GPS and over 833 km of driving, mixed approx. 70/30 highway / city, I've averaged 7.45 km / l of fuel, which works out to 21.04 mpg. I'm currently running BFG mud terrains at 255-85-16. I'm thinking possibly tire pressure could come up a bit, and also that my axle ratio may have been changed on this truck. The engine is running very well and is extremely quiet. Does this sound like I'm roughly where it should be? My friends truck is getting about 8.7 km / l under similar conditions...but he's running 10% lower RPM. I don't know how anyone is going to get 10km / l out of these trucks, but maybe it's possible. Has anyone run a 3" stainless exhaust throughout and worked out the fuel economy difference? My average speed would be about 110-115kph with occasionally higher bursts, but not many.
Fuel economy calculated
- Thread starter Martin White
- Start date
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err....what kindof truck?
I have the same tires on a stock bj70 3b, 5 speed and 373 gears, and I get more like 26 mpg.
Soon be back to 31's with the 16's back home on the 40.
I have the same tires on a stock bj70 3b, 5 speed and 373 gears, and I get more like 26 mpg.
Soon be back to 31's with the 16's back home on the 40.
mileage calculators available at this site:
http://jumk.de/calc/mileage.shtml
Usually, the metric units are expressed in L/100 kms, not kms/L.
Basically you are getting 21 Imp MPG, or 17.5 US MPG.
What truck is this...what engine, what tranny, what diff ratio? Can't start comparing unless you have some criteria to compare to...
My 13B-T, H55f, 4:11, and 255/85r/16 combo in my BJ74 uses approximately 11.11L/100 kms in mixed City/Hwy (mostly city) driving. That works out to 25.4 Imp MPG or 21.1 US MPG.
I recently noticed a 1L/100 kms decrease in fuel consumption. I switched my additive to the Canadian Lube Corp's Premium Diesel Conditioner, which has a cetane booster as well as the other properties that are desirable in diesel additives. http://www.piersdiesel.com/LubeCDNprice.htm However, Greg points out that we have recently switched over to summer fuel, and that may acount for the difference, although I have only switched during the last few tanks of fuel and we should have switched over to summer fuel a while ago.
Other things that will help with your fuel mileage...having your injectors serviced and your fuel pump timed, ensuring that you have a clean fuel filter, running a good fuel system cleaner like Lubro Moly Diesel Purge, valve set, etc.
BTW, my figures were obtained by my corrected speedometer, the adapter of which was designed by GPS measurement. Cheers.
http://jumk.de/calc/mileage.shtml
Usually, the metric units are expressed in L/100 kms, not kms/L.
Basically you are getting 21 Imp MPG, or 17.5 US MPG.
What truck is this...what engine, what tranny, what diff ratio? Can't start comparing unless you have some criteria to compare to...
My 13B-T, H55f, 4:11, and 255/85r/16 combo in my BJ74 uses approximately 11.11L/100 kms in mixed City/Hwy (mostly city) driving. That works out to 25.4 Imp MPG or 21.1 US MPG.
I recently noticed a 1L/100 kms decrease in fuel consumption. I switched my additive to the Canadian Lube Corp's Premium Diesel Conditioner, which has a cetane booster as well as the other properties that are desirable in diesel additives. http://www.piersdiesel.com/LubeCDNprice.htm However, Greg points out that we have recently switched over to summer fuel, and that may acount for the difference, although I have only switched during the last few tanks of fuel and we should have switched over to summer fuel a while ago.
Other things that will help with your fuel mileage...having your injectors serviced and your fuel pump timed, ensuring that you have a clean fuel filter, running a good fuel system cleaner like Lubro Moly Diesel Purge, valve set, etc.
BTW, my figures were obtained by my corrected speedometer, the adapter of which was designed by GPS measurement. Cheers.
Martin White said:
From your prior posts I assume it is an HDJ81 you have. I know Crusher has reported in the high 20's (27-28impg) or so on some road trips he has made with various trucks. Does your friend have the same sized tires? Mid 20's should be realistic with the 33" skinnies I would think. Sorry, no direct real world experience with one though.
hth's
gb
- Thread starter
- #5
Sorry, it's a JDM HDJ81, 1990
Auto trans, 255-85-16 tires, 2 1/2" lift. That's all the info. I have right now.
Auto trans, 255-85-16 tires, 2 1/2" lift. That's all the info. I have right now.
crushers
post ho
31" tires, stock gearing (4.11) auto 90 km/hr documented 27.8 mpg
same truck at 130 km/hr with bursts to 150 km/hr 21 mpg (this one is if memory is working)(it is recorded here on mud, do a search)
average mpg in an 81 (5 stock trucks tested) was 25 mpg
Gowyn got something like 25 mpg (it is posted here on mud, do a search) at 120 on a lifted 81 auto with 33" tires
same truck at 130 km/hr with bursts to 150 km/hr 21 mpg (this one is if memory is working)(it is recorded here on mud, do a search)
average mpg in an 81 (5 stock trucks tested) was 25 mpg
Gowyn got something like 25 mpg (it is posted here on mud, do a search) at 120 on a lifted 81 auto with 33" tires
Sorry don't have exact consumption figures for my truck but I know that if I cruise at 90-95kmh instead of my usual 100-105kmh I can get an extra 100-200km range out of my factory twin fuel tanks.
Tapage
Club 4X4 Panamá
In my HDJ-80 95 with 285/75 R16 stock gearing .. 1.5" lift .. never get more than 20 MPG .. city .. uff 16 MPG .. with good luck ! 
crushers
post ho
imperial gallons?
86 bj74 13bt 155000 kms, tires 245 75 16 - 80% Highway driving =
Liter per 100 km (l/100 km): 10.5
Miles per US-gallon (mpg): 22.38
Miles per UK-gallon (mpg): 26.85
Thanks
GB
Edit.... Average highway RPM - 2100
Liter per 100 km (l/100 km): 10.5
Miles per US-gallon (mpg): 22.38
Miles per UK-gallon (mpg): 26.85
Thanks
GB
Edit.... Average highway RPM - 2100
Last edited:
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Im getting between 7.2 and 7.4 km/l mostly city with lots of hills.
turboed 3B with 4.11s and 33's,
is this bad for this setup?
turboed 3B with 4.11s and 33's,
is this bad for this setup?
jzilla said:
Damn...what's with the KM'S/LITER???? Give us MPG or L/100 kms pls. Tired of converting everything to the conventional units.
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haha stone, yeah when i get my receipt after filling up i just find it's the quickest thing to do, so i always go by that, less calculating for me!
maybe im just bad at math
also wanted to go along with the first thread
maybe im just bad at math
also wanted to go along with the first thread
...while I have not yet filled up, I can note my trip to Phoenix and back I think I got 15 mpg (US).
HDJ74, m-t, 285/75/16, 4.11, average speed est 80-85 mph, rpm 2600-2700.
I was 20.6 on first tank with mixed highway (short trip) and city.
obviously the truck likes slower speeds, but driving 90km/hr on a 75 mph freeway would be death.
plus, the truck can do 100+ mph pretty easy. I must say passing in 5th from 80 to 85+ is nice compared to the 13B-T that all but died at 80 mph.
HDJ74, m-t, 285/75/16, 4.11, average speed est 80-85 mph, rpm 2600-2700.
I was 20.6 on first tank with mixed highway (short trip) and city.
obviously the truck likes slower speeds, but driving 90km/hr on a 75 mph freeway would be death.
plus, the truck can do 100+ mph pretty easy. I must say passing in 5th from 80 to 85+ is nice compared to the 13B-T that all but died at 80 mph.
Rick:
Fastest I ever take my BJ74 is 75 MPH (120 KMH). I have gone 80 MPH, but I don't like the way the engine sounds at that speed, so I just don't drive it that fast. Anyway, that was pre-pyro...now that I know what my EGT's are, I know I'm not going to go near that fast.
Fastest I ever take my BJ74 is 75 MPH (120 KMH). I have gone 80 MPH, but I don't like the way the engine sounds at that speed, so I just don't drive it that fast. Anyway, that was pre-pyro...now that I know what my EGT's are, I know I'm not going to go near that fast.
- Thread starter
- #17
It sounds like I'm getting relatively poor economy
I'm not sure why but you have all given me some things to check over. I will be posting with results in the future. Thanks for the help.
I'm not sure why but you have all given me some things to check over. I will be posting with results in the future. Thanks for the help.
Martin White said:
In addition to checking your timing, fuel filter etc...
Try some fuel injector cleaner.
Go to lordo and get some "Power kleen"
They have 3 different bottles.
They all do something slightly different.
They all lubricate, One is a general additve, one is made for cleaner injectors and the other is made for cleaning carbon ( I think). I usually rotate between all 3 bottles. They last for awhile and each bottle has a different mix ratio. Get the one made for cleaning injectors (orange I think, but make sure to double check). Run it pretty heavy (double dosage) for a few tanks and see how you do.
Also, once your diesel is good and warm, don't be afraid to work it a bit. They need to be worked every once and ahwile. Just make sure to give it cool down time.
Basically, run some cleaner and work her good.
Should clean it out.
Cheers,
Nick
Running over to Calgary from Salmon Arm Friday night, I got 8.3 km/l indicated (sorry Stone, but that's the way my head works - Makes it easy to convert to mpg - Multiply x 3 and subtract 5% Besides, I don't like doing reciprocals on my slide rule) - Top EGT on the hill going east of Field was getting close to 1100F - top temp to date... Running generally in the 110 km/h range, down to 90 on the hills....Normal EGT's in the 650 range at speed
Running back, got exactly the same consumption to the 4th decimal place, but the L/C was smoking bad on the hills until I got back to Field, where it smartened up after a rest stop - suspect one or two injectors are getting a little off...EGT's were 850 ish, and then dropped back to normal when the smoke reduced.
1HZ, Auto, 31x10.50 Blizzaks, 4:11's - and my speedo is non-linear. 10% high at 110 indicated = 100kmh, 63 indicated = 60 kmh - checked by GPS on the same trip. The odometer appears to be off between 5 and 10% currently. Need to do a tune.
Besides, I don't like doing reciprocals on my slide rule) - Top EGT on the hill going east of Field was getting close to 1100F - top temp to date... Running generally in the 110 km/h range, down to 90 on the hills....Normal EGT's in the 650 range at speedRunning back, got exactly the same consumption to the 4th decimal place, but the L/C was smoking bad on the hills until I got back to Field, where it smartened up after a rest stop - suspect one or two injectors are getting a little off...EGT's were 850 ish, and then dropped back to normal when the smoke reduced.
1HZ, Auto, 31x10.50 Blizzaks, 4:11's - and my speedo is non-linear. 10% high at 110 indicated = 100kmh, 63 indicated = 60 kmh - checked by GPS on the same trip. The odometer appears to be off between 5 and 10% currently. Need to do a tune.
Tapage
Club 4X4 Panamá
nap .. US gallons ..crushers said:
