A440F vs H55F Mileage: Direct comparison

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Joined
Apr 9, 2010
Threads
12
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156
Location
Billings, MT
I recently drove from Montana to Alaska... a drive that I do every Spring and Fall in my 1989 FJ62. This time, however, I had along a newly installed H55F to replace the original A440F. The new 5-speed had about 500 miles on the ticker when I set out. I have made no other changes to the truck which is completely stock down to stock-sized tires. I keep track of my gas mileage on these treks, so I can provide some data and observations about the mileage performance between the two set ups. I compared mileage of 12 tanks of gas along the same route. The drive provides a huge variety of highway driving, from high speed flats in parts of Montana and eastern WA to slow, hilly, frost heaved hell in Yukon.

So, to get to the results, with the auto my mileage averaged 17.6 mpg on these trips. With the 5 speed: 17.1 mpg.

I noticed a slight mileage drop on I-90 between Billings and Seattle with the 5 speed of about 1-1.5 mpg, like because of the higher rpm of the H55F vs. the auto. I tried to keep the rpms at or below 3000, that put me at about 72mph. On the lower speed limit roads in Canada and Alaska my mileage was slightly higher than the auto, but only by about 0.2 mpg.

So no significant change in gas mileage. The performance is night and day however. No downshifting required execpt for very steep hills, the truck is really "peppy" for a cruiser, especially compared to the way it used to act with the auto. I feel much more confident when I need to pass someone. The 3fe seems to thrive with the low-geared H55F below about 70mph. It is like a new vehicle and a complete pleasure to drive. I can't wait to get off road and try it in low range.

So if you're looking for a mileage increase the H55F swap is not going to give that, and like me you might see a slight drop due to the lower gearing of the H55F compared to the auto. But for me the way the truck drives is more than worth the cost and labor of putting in the new tranny. The truck feels like it is ready for another 300,000 miles and is a blast to drive.

So nothing new here from what many others have suggested about mileage for a 62 with an H55F, but it does give some "proof". As another MUD poster suggested, too bad they don't make an "H66F" 6-speed tranny.
 
I wonder what the difference would be if you kept the final drive ratio the same by either regearing or larger tires. I doubt anyone would try to argue you'll get better mileage with the manual when 4th gear on the auto is longer (by a bit) than 5th the manual. Maybe on your next trip you can regear or get bigger tires and have the ultimate comparison. 12 tanks of gas over varied terrain (presumably same time of year) is a great amount of data.
 
I'm off maybe a .5 gallon highway and almost exactly the same city between my A440 and H55. I think that this is due to two things - gearing (as previously mentioned - there is about a 12% difference between the O/D). The other is how rich a 3FE runs at higer rpms and how easily it goes into open loop (I have a wideband O2 on mine: https://forum.ih8mud.com/60-series-wagons/421776-lc-1-wideband-o2-pc-install.html - I'm making progress on the MAF conversion mentioned in this thread). So I guess this is really only one thing, because the steeper gearing means higher rpms which means more fuel cycles and the higher rpms seem to contribute to going into open loop and running richer.

The minor mpg change doesn't matter though, the improvement in driveability is well worth it.
 
Swapping gears won't help. It has been tried with an HZ-T and resulted in less drivability. Maybe if you kept ~30" tires it could work. We were looking at 4.11 vs 3.70 on 33" tires.

Really need a 6spd or a taller OD gear in the H55. I wanted to keep my A440 with the HZ swap partly for the tall OD gear, but after looking at the cost for essentially a rebuild, billet TC, cooler, and valve body matched to the engine you look at about $5000. This was when AUD was .60:1 USD. (currently it is just over 1 AUD : 1 USD)
 
What size tires are you running? Your speedometer and odometer are set up for a tire thats only about 29 in tall, check the door tag it left the factory with 225 75R15 tires. If you are running 31 or 33's your speedo is off by quite a bit. Just a thought... Might want to look at your mpg once the speedo is corrected for tire size. A 33 in tire will put the speedo off more than 10% as well as the odometer and not to the good either.

I am jealous if you are getting a real 17 mpg out of a 62, never got better than 14 out of mine. But my BJ 60 gets 22 so I don't feel so bad now even though calling it slow would be generous....

Tony
 
Swapping gears won't help. It has been tried with an HZ-T and resulted in less drivability. Maybe if you kept ~30" tires it could work. We were looking at 4.11 vs 3.70 on 33" tires.

Really need a 6spd or a taller OD gear in the H55. I wanted to keep my A440 with the HZ swap partly for the tall OD gear, but after looking at the cost for essentially a rebuild, billet TC, cooler, and valve body matched to the engine you look at about $5000. This was when AUD was .60:1 USD. (currently it is just over 1 AUD : 1 USD)

I don't understand why swapping gears won't help but a taller OD would. Was the drivability issue only in first-fourth? I'm running 4.56 gears with 265/75r16s (31.5" tall). Per GPS my speedo is dead on. Ideally I'd prefer just a taller OD but swapping back down to 4.11 seemed like a reasonable option.

Of course my other approach to addressing this is to delay the aggressive onset of open loop via my programmable MAF conversion. At this point it starts and sort of idles :D. More tuning this weekend.
 
What would be really interesting is a comparison of offroad or town fuel consumption, when the A440Fs torque converter isn't locked up. I'd expect highway consumption to be very similar.
 
What size tires are you running? Your speedometer and odometer are set up for a tire thats only about 29 in tall, check the door tag it left the factory with 225 75R15 tires. If you are running 31 or 33's your speedo is off by quite a bit. Just a thought... Might want to look at your mpg once the speedo is corrected for tire size. A 33 in tire will put the speedo off more than 10% as well as the odometer and not to the good either.

I am jealous if you are getting a real 17 mpg out of a 62, never got better than 14 out of mine. But my BJ 60 gets 22 so I don't feel so bad now even though calling it slow would be generous....

Tony

235/75/15 with mellow tread. They are getting close to the end of their lives so probably close to 225s. I checked the speedo with a gps, it is pretty close.

This is all highway, any city driving at all and I get 12-14 at best.
 
I don't understand why swapping gears won't help but a taller OD would. Was the drivability issue only in first-fourth? I'm running 4.56 gears with 265/75r16s (31.5" tall). Per GPS my speedo is dead on. Ideally I'd prefer just a taller OD but swapping back down to 4.11 seemed like a reasonable option.

Yep, the issue is with how 2-4 work. They are great utility gears and spaced pretty well (3rd is too low for me). 1st is useless except for offroad, steep hills or otherwise control situations, but it rocks then.

The OD gear should hit a target cruising speed (60 or 65 or 70 whatever) as close to max torque RPM for greatest efficiency. 3FE and 1HZ develop max torque at 2200 according to specs. As is, it revs too high (or we are just trying to go too fast!).

Maybe one day there will be an HD continuously variable transmission available.
 
I'm really surprised by this.
I always thought the H55F would be more efficient, that the less tall 5th gear would still easily be more efficient than the taller 4th O/D gear of the A440F, with the TC lockup not being as efficient as it could be and the fluid pump's drain.

Does this apply to all 60 engines, or will say a 2F or even a 2H or 12HT respond differently again?
 
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17.1 with a five speed sounds good.

17.6 with an A440F sounds utterly unbelievable. I am not saying I don't believe the thread starter, as all seems very well documented, so please don't take offense.

However, most people in a 62 don't see anything beyond 12 to 14 mpg, so getting up to 17 would be a big improvement.

The well tuned 62 I had a long time ago (OME lift and 33x12.5 tires, so not really comparable) never went beyond 10mpg, when any weight was in there.

cheers,
jan
 
I think the key piece of info here is the production tires and gearing. His torque converter is locked nearly all of the time thus mimmicking the manual trans at highway speeds. The efficiency losses of the auto are likely offset by those of the engine spinning faster (more pumping losses) with the manual.

Since the 4 speed revs the engine so darn high I can't compare it to my 60. Heck, if I could get that out of a 5 speed though that would sure be nice.

Frank
 
The highest I've ever gotten (and only once) was 17 MPG. It was on HWY 2 between Spokane and Everett, WA on stock tires, keeping no higher than 65 the entire way. I've gotten 16 MPG on a few occasions, but that's till pretty rare. My average now when all highway is 14-14.5 MPG, with about 12-13 MPG in the city. This is with stock gearing, 31" mudders, and an electric radiator fan (no drag on the engine from a clutch fan). I'm still very curious to see what my H55 gives me with the stock 4.11 gears and 33" A/Ts once it's in.
 
Yep, the issue is with how 2-4 work. They are great utility gears and spaced pretty well (3rd is too low for me). 1st is useless except for offroad, steep hills or otherwise control situations, but it rocks then.

The OD gear should hit a target cruising speed (60 or 65 or 70 whatever) as close to max torque RPM for greatest efficiency. 3FE and 1HZ develop max torque at 2200 according to specs. As is, it revs too high (or we are just trying to go too fast!).

Maybe one day there will be an HD continuously variable transmission available.

On my 60 with an H55+3,70's+33" tires it is spinning 2081 @65mph and 2242 @ 70 mph in 5th. This seems to be what he needs to be at for the 3FE.

I can't compare mileage as mine is a diesel, but I think with a gear change his mileage with the H55 would be equal to, or better than with the auto.

Doug
 
17.1 with a five speed sounds good.

17.6 with an A440F sounds utterly unbelievable. I am not saying I don't believe the thread starter, as all seems very well documented, so please don't take offense.



No offense taken, I guess I am just lucky or something but my mileage has always been better than I have seen posted for others on MUD, for highway anyway. The cruiser does better than my 1988 Toy pickup, but that has big mudder shoes. The most I ever got was 19mpg on one tank between Edmonton and Calgary on one of my trips, have had some more in the 18's here and there. I have pushed the trip odometer over 400mi. once on one tank, regularly get into the high 300's. In the city I am in the same ballpark as everyone else. As I said I confirmed my speedo with a gps. I attribute it partially to my tires (Nokian Vatiiva 235/17/15) which embarrassingly are pretty much street tires, although great on ice. Cruise control probably helped too (now doesn't work since the 5 speed install). I also drive super conservatively, but with the 5-speed that is changing!
 
Sorry about the messed up "quote" above...

Also this is just for this particular route and trip, which is pretty much zero city driving. Most "usual" tanks (some city, mostly highway) I am more in the 12-14mpg ballpark.

Even if my numbers turn out to be "unnaturally" high, I thought it was interesting that the numbers were so close between the auto and the manual. I, too, had hoped for a little improvement. I am planning on taller tires for my next set, I'll post the results then too.
 
I don't think you are comparing apples to apples.

4.11 with A440F vs 4.11 to H55F is not at all equal. Why? Toyota gears it's automatic tranny trucks different than manual tranny trucks. The FJ60 had 3.70 gears while the FJ62 had 4.11. Even in the mini-truck world the manual tranny trucks had 4.56 gears (with 31" tires) while the automatic trucks had 4.88 gears (again with the 31" tires).

I'm willing to bet that if you took your tires to 33" to put the gear ratio where Toyota intended it your highway rpm would come down, and your mileage would go up with the H55F. Of course your speedo would be messed up, but it's easy to do the math.
 
I don't think you are comparing apples to apples.

4.11 with A440F vs 4.11 to H55F is not at all equal. Why? Toyota gears it's automatic tranny trucks different than manual tranny trucks. The FJ60 had 3.70 gears while the FJ62 had 4.11. Even in the mini-truck world the manual tranny trucks had 4.56 gears (with 31" tires) while the automatic trucks had 4.88 gears (again with the 31" tires).

I'm willing to bet that if you took your tires to 33" to put the gear ratio where Toyota intended it your highway rpm would come down, and your mileage would go up with the H55F. Of course your speedo would be messed up, but it's easy to do the math.

Depends a bit on the market.
The central american HJ60s had a 5 speed and 4.10 gears. Don't know about the canadian manual HJ60s.
cheers,
J
 
Yep, the issue is with how 2-4 work. They are great utility gears and spaced pretty well (3rd is too low for me). 1st is useless except for offroad, steep hills or otherwise control situations, but it rocks then.

The OD gear should hit a target cruising speed (60 or 65 or 70 whatever) as close to max torque RPM for greatest efficiency. 3FE and 1HZ develop max torque at 2200 according to specs. As is, it revs too high (or we are just trying to go too fast!).

Maybe one day there will be an HD continuously variable transmission available.

I wonder if we are using "up" and "down" differently in regards to gearing. I mean gear down numerically. For example I cruise at 65-70 and currently turn 2900 rpms at 70. For me gearing down makes sense, as it will put me between 2600-2700rmp at 70 and 2200rpm at 60 (although I have a custom cam and peak torque is probably closer to 2400 for me). This is about what I had with the A440's .73 OD, 4.56s and 31.5s. I don't believe that this will negatively impact my 1-4th experience. In fact first should be a bit more usable. Thoughts?
 

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