Why I love my 80 HDFT turbo diesel (1 Viewer)

[Workhorse]

Here is my best tank of diesel (Factory main only) ever (so far), 556.2 miles and when filled up (to the filler cap) took 22.52 gallons (US) which is roughly 24.7MPG (US). I'm glad I went Factory HDFT turbo diesel ten years ago and will never ever look back. I love my manual 80 HDFT. I wonder if the HDJ100 can boast similar numbers, those trucks are super rad too.

Anyone else have a best tank ever story to share?

 

[IanB]

Those are big numbers! I'm very curious what your exterior looks like to hit numbers like that, do you have a pic? Always wondered what penalty the window visors and bumpers, mudflaps, etc do to the fuel economy potential.

 

[jakerudy]

My FJ60 with a 6BT gets a little over 20 mpg but can't match your results. Due to my daughter's future plans I'll probably switch from MT's to AT's for better highway manners so that may improve mpg a little.

My calculations have always been an estimate as my speedo / odo was about 15% off due to tire size. The cable broke and I'm replacing it with a Speedhut GPS gauge so should be able to get a more accurate reading soon.

 

[Squash]

Nice!
I'm pulling a trailer and two RRT's and my 1991 HDJ81 is getting almost double what the SC'd 80 gets.

 

[Workhorse]

@IanB Here is a photo, please forgive the delay. I just finished putting the Bowfin roof rack on it last night from @dogfishlake so we will have to see what that does to the diesel mileage. I haven't weighed it but I have lots of heavy gear like bumpers front and rear, winch, sliders and all sorts of goodies inside too like drawers, fridge with fridge slide etc.

 

[dogfishlake]

@IanB Here is a photo, please forgive the delay. I just finished putting the Bowfin roof rack on it last night from @dogfishlake so we will have to see what that does to the diesel mileage. I haven't weighed it but I have lots of heavy gear like bumpers front and rear, winch, sliders and all sorts of goodies inside too like drawers, fridge with fridge slide etc.

View attachment 2268404

She'll pick up at least 2mpg!

Seriously, I have never heard of a change in mileage but also don't know of anyone making a dedicated comparison experiment (including myself!). It would be good info to have.

Your truck looks sweet. I love the steel 80 wheels.

 

[Indestructible 47]

They are a really good engine. Up one again is the 1hd-fte. But it depends how you drive that makes the biggest difference. I can get a clear 200km difference in a tank if I drive at 120km/h vs 100km/h. Thats a fte

 

[Dork]

In my HDFT, I've had best tanks of around 12.5L/100km, but that's when keeping it under 90kph. I'll normally be sitting more like 15L/100 in a city/highway mix. Google says those are 19mpg-15mpg numbers.

That's with a lift and 315s to help ruin aerodynamics.

 

[ofer bruhis]

I get 22-26 cruising at 60 mph and 17-18 when crawling in the desert in 2-3rd gears (H151) BFG 295/75R16.. I think it also depends on your injector pump tune, how much boost, intercooler, etc. Did the conversion from 1FZ-FE in 2018 and in over a period of 16 months I did 26000 miles. Alaska, and a few close states to Bay Area, CA. Love the truck. Will never ever sell it, for whatever money they offer.

 

[AussieHJCruza]

The best I could get with 1HDT was about 20.2 mpg, with Gturbo redwheel, injectors, pump, 3" zaust, 600x400x76 cross country cooler, moonlight airbox, etc etc, plus network, tyres and all that to ruin the aerodynamics, plus H151.
I couldn't get better than about 17 pre all the mods, but the fuel pump was tired so definitely wasn't at its peak when stock.

 

[ofer bruhis]

The best I could get with 1HDT was about 20.2 mpg, with Gturbo redwheel, injectors, pump, 3" zaust, 600x400x76 cross country cooler, moonlight airbox, etc etc, plus network, tyres and all that to ruin the aerodynamics, plus H151.
I couldn't get better than about 17 pre all the mods, but the fuel pump was tired so definitely wasn't at its peak when stock.

One thing I noticed that the mpg is opposite related to the age of the driver.

 

[Moridinbg]

Those are mighty impressive numbers. 22.5 us mpg is ~10.5 l/100. The only way my HDJ100 will do that is with highway tires and cruising at <100kmh (60mph). I average 13/100 cruising @ 120kmh with Maxxis MT tires.

 

[FJBen]

@IanB Here is a photo, please forgive the delay. I just finished putting the Bowfin roof rack on it last night from @dogfishlake so we will have to see what that does to the diesel mileage. I haven't weighed it but I have lots of heavy gear like bumpers front and rear, winch, sliders and all sorts of goodies inside too like drawers, fridge with fridge slide etc.

View attachment 2268404

You don't happen to or used to live in Northern Colorado did you?

 

[joseywales]

You don't happen to or used to live in Northern Colorado did you?

Right there in the “location” part of his post it says “CO USA”, so I’m going to take a guess that he is from Colorado?

 

[FJBen]

Right there in the “location” part of his post it says “CO USA”, so I’m going to take a guess that he is from Colorado?

Yes, but there's northern colorado, western slope, southern colorado, The front range...which is why I asked northern colorado as I remember seeing a diesel 80 series a few years ago looked just like that around there.

 

[ofer bruhis]

Those are mighty impressive numbers. 22.5 us mpg is ~10.5 l/100. The only way my HDJ100 will do that is with highway tires and cruising at <100kmh (60mph). I average 13/100 cruising @ 120kmh with Maxxis MT tires.

The best I got was 25.9mpg on a 500 miles (out and return 250 miles same day) ride only on the freeway with no roof rack and driving at 60 mph. I used the map and odometer to verify the distance and filled the fuel slowly until it spilled. It was only one stop so it was all done in fifth gear. The car is also set to part time, so was driving in 2WD. At that time I had no intercooler.

 

[AussieHJCruza]

One thing I noticed that the mpg is opposite related to the age of the driver.

OK, that would be my problem then!

 

[AussieHJCruza]

Those are mighty impressive numbers. 22.5 us mpg is ~10.5 l/100. The only way my HDJ100 will do that is with highway tires and cruising at <100kmh (60mph). I average 13/100 cruising @ 120kmh with Maxxis MT tires.

I found the same, if I sat on 100km/h I would get 20mpg, If I did 115, I'd go back to 17mpg.

 

[ofer bruhis]

OK, that would be my problem then!

It would also depend on how the injector pump is tuned. Do you have black smoke coming out when accelerating?

 

[AussieHJCruza]

It would also depend on how the injector pump is tuned. Do you have black smoke coming out when accelerating?

It was tuned to 17:1 AFR on spool and 20:1 on boost to the governor. Puff of black off the mark, EGTs stable on a long hard pull at about 700c, timing at 1.3mm lift as per pump builders spec and 26 psi of boost. 160rwkw and 610 rwnm from memory.
Seriously miss that truck...