HDJ81 fuel consumption test run
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I guess you'll be able to spot me pretty easy. I'll be that guy in the 81 driving like and old lady and pissing everyone off. I think my truck drives horrible over 110 km/hr, and yes its well maintianed. It got a stock suspension and new bfg 31's with the right air pressure. It tracks fine, and there is nothing wrong with it. I just hate the noise from the engine screaming.
I just don't think they have the right gears for sustained speeds like that and I don't like the roar and the lower mpgs. My old 4runner ran the same rpm's for those speeds with a 4cyl that redlined at much higher numbers......
I just don't think they have the right gears for sustained speeds like that and I don't like the roar and the lower mpgs. My old 4runner ran the same rpm's for those speeds with a 4cyl that redlined at much higher numbers......
No... is an auto...
I guess I'm just a bit more delicate with the truck. I see big difference in fuel economy between 100-115km/hr on the highway. Probably a difference of 100-150km/tank of fuel. The numbers people post seem pretty optimistic to me.
I rented a new V8 explorer and drove to Montana for work (120-140km/hr the whole way it being a rental I didn't baby it) at 130km/hr its only turing 2000rpm. At 2000rpm in my 81 I'm doing 90km/hr.
It's my first diesel. Maybe they are made to rev like hell for hours on end. Everytime I hit 3000rpm I cringe a little.
I hear with the manual 5th gear is not so great for the highway. But I guess they would save some energy with the 4WD vs AWD powertrain drag (as I understand the 5sp trucks are 4WD not AWD).
DW
I guess I'm just a bit more delicate with the truck. I see big difference in fuel economy between 100-115km/hr on the highway. Probably a difference of 100-150km/tank of fuel. The numbers people post seem pretty optimistic to me.
I rented a new V8 explorer and drove to Montana for work (120-140km/hr the whole way it being a rental I didn't baby it) at 130km/hr its only turing 2000rpm. At 2000rpm in my 81 I'm doing 90km/hr.
It's my first diesel. Maybe they are made to rev like hell for hours on end. Everytime I hit 3000rpm I cringe a little.
I hear with the manual 5th gear is not so great for the highway. But I guess they would save some energy with the 4WD vs AWD powertrain drag (as I understand the 5sp trucks are 4WD not AWD).
DW
Your experiences are normal. The drag force on your truck at 115km/h is 30% higher than at 100km/h, the power required at 115km/h is 50% higher than at 100km/h. It's normal to see it using 20-30% more fuel if you travel at this speed.
There are some ludicrous fuel consumption claims on this board. To the point where new vehicle owners have been disappointed with them.
Diesels this size are most efficient at around 1800-2000rpm, best efficiency is almost always at the same rpm as peak torque. While they are built to survive running at high rpms all day, the efficiency drops as the revs climb, compounding the fuel usage.
I`m very pleased with 12-13litre/100km i get, probably could do better if i babied it but diesels dont last the same when babied.
Lately i`ve had my 3.5ton dump in tow which returns anywhere from 14-18litres/100km.
As for the speed thing after having driven many early 1hdt 80`s i thought they were scary much over 130kmh and was about to skip to a 100 but after driving my 97 found it feels very solid at 180kmh.
Previously i owned two 3.1 Isuzu Bighorns which were good for light towing/daily driving.Rubbish offroad rather slow and economy was poor compared to the 80.
Lately i`ve had my 3.5ton dump in tow which returns anywhere from 14-18litres/100km.
As for the speed thing after having driven many early 1hdt 80`s i thought they were scary much over 130kmh and was about to skip to a 100 but after driving my 97 found it feels very solid at 180kmh.
Previously i owned two 3.1 Isuzu Bighorns which were good for light towing/daily driving.Rubbish offroad rather slow and economy was poor compared to the 80.
crushers
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once again you boldly call mud members liars....damn you got balls Roverboy.
it seems your posting about the capability and fuel economy for the 3.1 Isuzu is not backed by diesel junkie...
i guess you are lying as well...eh? or maybe you don't have your book worm facts straight... or maybe you will call diesel junkie a lier since he doesn't agree with the bull s*** post you made?
damn, your facts are slipping Roverboy.
Don't get me wrong I' m really happy with the truck. Somtimes just wish it had a more modern highway transmission (maybe a double over drive). But then again you would likely give up reliability that has made the truck so famous. On the gravel at 60-80km'hr its a real champ, sometimes just needing a little manual bump down to 3rd on the big hills at the right time.
Also, from what I've read they are not designed for sustained load at low rpms, the engine seems to have really low a oil pressure at low rpm, so the higher revs build up the proper oil pressure to load bearings with out overstressing the surfaces. It's just what I've read, but like all things on line ....the thruth could be anything.
Also, from what I've read they are not designed for sustained load at low rpms, the engine seems to have really low a oil pressure at low rpm, so the higher revs build up the proper oil pressure to load bearings with out overstressing the surfaces. It's just what I've read, but like all things on line ....the thruth could be anything.
You're quite welcome to ignore my findings. But I personally ran those two vehicles up my same benchmark hill. The 3.1TD bighorn was 10km/h faster over the top than the 1HD-FTE cruiser.
The 1HD-FTE 100 series spanks the 1HD-TE 80 series, but it's still 14 seconds to 100km/h.
Your pettiness is outstanding.
BTW I'm not "calling mud members liars". There's only one member who's made such ludicrous claims (you) and you may not be lying, you may simply be mistaken. You may not know that a fuel consumption calculation off a simple fillup has a massive margin of error.
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crushers
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oh but we are supposed to believe you even though the only other poster about the same engine states the very oposite when it comes to fuel milage (which BTW agrees with the information i recieved from Japan that they are powerhouses but s***ty fuel milage)...
but then in your books he is just lying with "such ludicrous claim". or i guess he could be mistaken with his figures.
Hmm, i wouldn`t them powerhouses, whilst they hold nice speed i found overtaking at openroad speeds quite scary, you would need a good 1km to make a pass safely.
My first Bighorn i owned 4years (tranny rebuild) and 2nd one three years (2 cracked heads).
There`s about 1 second 0-100kmh between the 1hdft & 1hfte but this changes dramatically with off boost fuel response adjustment and even more so with 3inch exhaust.
Just my own personal real life experience
My first Bighorn i owned 4years (tranny rebuild) and 2nd one three years (2 cracked heads).
There`s about 1 second 0-100kmh between the 1hdft & 1hfte but this changes dramatically with off boost fuel response adjustment and even more so with 3inch exhaust.
Just my own personal real life experience
If I want to call someone a liar, I'll do it. It's not really a problem. I haven't called you a liar because it's obvious you believe in the figures you've got, despite them being ridiculous.
So despite your contempt for "book knowledge", here you're quoting something you read?
Gee that's consistent.
The people I know with troopers are getting better fuel economy than the people I know with landcruisers.
But due to the troopers having more power, they drink more if driven harder/faster. (duh).
Yes they are much faster, yet in the japanese 10-15 cycle get better than 10km/l.
http://specs.amayama.com/specs-isuzu-bighorn-1999-october/13460/
Some owners impressions of fuel economy: http://www.itocuk.co.uk/forums/viewtopic.php?t=6584
A poor attempt at putting words in my mouth.
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I personally have no idea where you're getting your fuel consumption figures for an 80 series from. 80 series are something like 2800kg kerbweight, look somewhat akin to a brick (much like a 70 series) with very few more curves and your quoted 19.01mpg (imperial... british). Which is something akin to 14.86L/100km.
At 150kmh? Right. Ok. Sure.
I know a -lot- of 80 series owners here in Oz. They are staple vehicles for families and turbodiesel auto ones are EVERYWHERE. I don't think any of them return better than 14L/100km on the highway at 100kmh let alone 150kmh.
My 70 series struggles to better 15L/100km @ 100kmh with a kerbweight of 2960kg and the aerodynamics of a brick on wheels. I'm a bit skeptical.
I don't doubt for a moment that those are the figures you got, but I HIGHLY HIGHLY doubt they are what anyone would term "regular". I'm not going to stick up for dougal here as I haven't done the frictional drag calculations (even quickly although my physics book is behind me), but it doesn't seem too far off that about 40-50% more power (kW/hp) is required for a difference in speed of 100-115kmh on a car with a drag coefficient so high as a 80 or 70 series. And if you had a headwind... well, come off it. You're trying to tell us that you can regularly pull sub 12L/100km figures from your 3 tonne truck?
I'm calling shenanigans. Either that or you have a "Factory freak" because those numbers are definately not normal. Don't forget that it's constant 4wd... part timers use less fuel due to less parasitic drag in the geartrain. Only one diff to turn, not three.
It's my understanding that torque convertors in the auto also contribute to parasitic drivetrain losses and thus increase fuel consumption... Although I do know from experience that an 80 series will pull about 165/170kmh at full tilt. But dear god they sway and blow around. Maybe not in canada, but here in oz we have WIDE OPEN PLAINS with -MAD- crosswinds. You just don't go that fast in a giant brick Hell, I have issues clocking 150-160 in a dedicated circuit car on the open highway courtesy of some of the winds.
At 150kmh? Right. Ok. Sure.
I know a -lot- of 80 series owners here in Oz. They are staple vehicles for families and turbodiesel auto ones are EVERYWHERE. I don't think any of them return better than 14L/100km on the highway at 100kmh let alone 150kmh.
My 70 series struggles to better 15L/100km @ 100kmh with a kerbweight of 2960kg and the aerodynamics of a brick on wheels. I'm a bit skeptical.
I don't doubt for a moment that those are the figures you got, but I HIGHLY HIGHLY doubt they are what anyone would term "regular". I'm not going to stick up for dougal here as I haven't done the frictional drag calculations (even quickly although my physics book is behind me), but it doesn't seem too far off that about 40-50% more power (kW/hp) is required for a difference in speed of 100-115kmh on a car with a drag coefficient so high as a 80 or 70 series. And if you had a headwind... well, come off it. You're trying to tell us that you can regularly pull sub 12L/100km figures from your 3 tonne truck?
I'm calling shenanigans. Either that or you have a "Factory freak" because those numbers are definately not normal. Don't forget that it's constant 4wd... part timers use less fuel due to less parasitic drag in the geartrain. Only one diff to turn, not three.
It's my understanding that torque convertors in the auto also contribute to parasitic drivetrain losses and thus increase fuel consumption... Although I do know from experience that an 80 series will pull about 165/170kmh at full tilt. But dear god they sway and blow around. Maybe not in canada, but here in oz we have WIDE OPEN PLAINS with -MAD- crosswinds. You just don't go that fast in a giant brick
Hell, I have issues clocking 150-160 in a dedicated circuit car on the open highway courtesy of some of the winds.
crushers
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LOL!!
i guess Gowan better never read this thread cause he drove from Calgary Alberta to London Ontario with the best milage of 33 mpg and worst of 28 mpg in a HDJ81...
i don't think he will apreciate being called a liar either...but when the dust settles, if you get 14L/100 at sea level and SOME of us are getting high 20s at 3500 ft then maybe it is time for you blokes to move to higher ground...
in the end, if you are only getting 19 mpg then why are you bothering with a diesel 80? the 1994 gasser is slightly worse fuel milelage and way more fun to drive.
if i drove a diesel that got any less than 22 mpg i would sell it.
i guess Gowan better never read this thread cause he drove from Calgary Alberta to London Ontario with the best milage of 33 mpg and worst of 28 mpg in a HDJ81...
i don't think he will apreciate being called a liar either...but when the dust settles, if you get 14L/100 at sea level and SOME of us are getting high 20s at 3500 ft then maybe it is time for you blokes to move to higher ground...
in the end, if you are only getting 19 mpg then why are you bothering with a diesel 80? the 1994 gasser is slightly worse fuel milelage and way more fun to drive.
if i drove a diesel that got any less than 22 mpg i would sell it.
crushers
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alittle bit of heads up:
the auto has a lockup torque convertor which elimate almost all the parasitic loss of the auto...
in your 70 series brick you are only getting 15L/100???? is that the old 3B or which motor? here the 3Bs get WAY better than that... ask Bruce (lowenbraw. Craig (lumpy), even Peter (Behemoth), Charla or anumber of other BJ70 owners on the forum...
the auto has a lockup torque convertor which elimate almost all the parasitic loss of the auto...
in your 70 series brick you are only getting 15L/100???? is that the old 3B or which motor? here the 3Bs get WAY better than that... ask Bruce (lowenbraw. Craig (lumpy), even Peter (Behemoth), Charla or anumber of other BJ70 owners on the forum...
I personally have no idea where you're getting your fuel consumption figures for an 80 series from. 80 series are something like 2800kg kerbweight, look somewhat akin to a brick (much like a 70 series) with very few more curves and your quoted 19.01mpg (imperial... british). Which is something akin to 14.86L/100km.
At 150kmh? Right. Ok. Sure.
I know a -lot- of 80 series owners here in Oz. They are staple vehicles for families and turbodiesel auto ones are EVERYWHERE. I don't think any of them return better than 14L/100km on the highway at 100kmh let alone 150kmh.
My 70 series struggles to better 15L/100km @ 100kmh with a kerbweight of 2960kg and the aerodynamics of a brick on wheels. I'm a bit skeptical.
I don't doubt for a moment that those are the figures you got, but I HIGHLY HIGHLY doubt they are what anyone would term "regular". I'm not going to stick up for dougal here as I haven't done the frictional drag calculations (even quickly although my physics book is behind me), but it doesn't seem too far off that about 40-50% more power (kW/hp) is required for a difference in speed of 100-115kmh on a car with a drag coefficient so high as a 80 or 70 series. And if you had a headwind... well, come off it. You're trying to tell us that you can regularly pull sub 12L/100km figures from your 3 tonne truck?
I'm calling shenanigans. Either that or you have a "Factory freak" because those numbers are definately not normal. Don't forget that it's constant 4wd... part timers use less fuel due to less parasitic drag in the geartrain. Only one diff to turn, not three.
It's my understanding that torque convertors in the auto also contribute to parasitic drivetrain losses and thus increase fuel consumption... Although I do know from experience that an 80 series will pull about 165/170kmh at full tilt. But dear god they sway and blow around. Maybe not in canada, but here in oz we have WIDE OPEN PLAINS with -MAD- crosswinds. You just don't go that fast in a giant brick
He did not do that at the speeds you are talking about. Impossible. You'd have to be driving like a serious grandmother to get 30mpg...
Incidentally, I can get 12-15L per 100km, depending on how I drive.
crushers
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the post said he was doing 110...
i did a search and can not find ANY of his posts so he might have come back and deleated them after selling his rig...
in any case, believe what you will...he had no reason to lie but then he might have been exagerating...
so, just in case my math really sucks...
622 km and took 60L to fill... what is that in L/Km and Km/L and american mpg and british mpg??
i did a search and can not find ANY of his posts so he might have come back and deleated them after selling his rig...
in any case, believe what you will...he had no reason to lie but then he might have been exagerating...
so, just in case my math really sucks...
622 km and took 60L to fill... what is that in L/Km and Km/L and american mpg and british mpg??
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Well apparently the altitude is really playing a part then. Most of our driving is at sealevel, and in Australia there's almost always wind acting on you in some direction.
My FRESHLY rebuilt 1hz with a BRAND NEW OEM injector pump and injectors and so forth -never- returns better than 15L/100km. Ever.
I was rather disappointed but apparently none of the guys I know down here get better than 14L/100km on their 1hz's either. I'm hoping a turbo will fix the issue.
My FRESHLY rebuilt 1hz with a BRAND NEW OEM injector pump and injectors and so forth -never- returns better than 15L/100km. Ever.
I was rather disappointed but apparently none of the guys I know down here get better than 14L/100km on their 1hz's either. I'm hoping a turbo will fix the issue.
You keep missing the point.
A single fill is useless to calculate a fuel consumption figure.
Even the slope on the gas station forecourt has a huge effect.
