4.88 vs. 4.56 in a 2006

[Redline]

I'm looking forward to this as well. I won't have an apples to apples Chaser towing test to be able to refer to, but I will have plenty of subjective opinions. I do know that with the super tall 3.73 and my 255/85 that the car would either loose lots of steam up hills to stay in locked overdrive, or could be downshifted and still move up grades. Now overdrive will do the work on most grades, there will be much less down shifting, and the tranny should be happier overall.

Though I was not pulling more that the V8 4Runner is rated to pull with my 7,000-lb Avion (optimistic rating?) it was still a very heavy load for the car. Living at altitude and pulling hills I just can't imagine pulling the same weight/trailer with 3.73. The tranny would likely get hot easily and I just can't see it working well. With the 4.88s the 4Runner got the trailer moving easily. On long grades opened-up in 3rd the little V8 was strong and worked well. My old Power Stroke is much better for pulling the heavy travel trailer. Though anything that weighs less should be very easy for the 4Runner now.

Next weeks camping trip in the eastern sierras will be at least 300 miles round-trip, hopefully with some high altitude dirt driving and four-wheelin'. I think that high-range with the 4.88s will be much more usable in the dirt, even when pulling the Chaser. This could make off-highway fuel economy a little better, reserving low-range for when it is truly needed. I see a distinction between common dirt roads and slow speed 4x4 use.

I thought there might me a slight fuel economy loss and it appears there is, but this may be because of how I was driving the car. Others that drive their modified rigs harder/faster/less carefully might be getting lower MPG and therefore going to a lower gear ratio lets the car not work as hard. So far the fuel economy hit is not so terrible that I'm unhappy about it. The performance (TORQUE) improvement is terrific! I will always have enough gearing to pull any reasonable load and my crawl ratio is creepy crawly 44.0:1.

I will never know how much less 4.56s would pull or if they would offer noticeable better fuel economy. Every platform and application is different.

:bowdown: Thanks for the detail update. The true benefit of the 4.88 should be even more obvious when you hook up the trailer in full travel mode.

 

[Redline]

Surprisingly, the pull to the right was not from the gears or alignment. It was from the new Toyo MT 255/85 tires, more comments will be posted in the recent Toyo MT thread.

Les Schwab did the alignment. Today I went back and a different guy, a young kid with one year experience/fresh out of school, fixed it up. He drove and I rode with him before and after. There was plenty of caster, but it still had a slight pull to the right, he felt it too. He said that sometimes vehicles with much larger than stock tires will need more caster on one side (the right) than the other to help compensate for the crown of the road. He set it up that way and it drove well.

I'm pretty sure there is some additional steering/torque sensation through the steering wheel with these lower gears (separate from the cater issue). There certainly is more torque and it drives/steering a little different/heavier, not bad, but I notice it. Still analyzing it. For those that don't know, the V8 4Runner is all-wheel-drive, it can't be put into 2WD. snip........

 

[jbs]

Redline,
Glad you are happy with your new gears. I am really wanting to do the same, but I'm not sure my wife can live without the truck for that long. What was the total install time and ballpark cost (if you don't mind)? Obviously both will vary by installer, but just curious how long I'd have to rent a car. What break-in procedure did you follow?

Finally, anyone know of a reputable installer in the Austin area? This might be the biggest hurdle for me, as 4x4 shops are fewer around here...

Another general question: I've always heard not to tow in OD. I assumed this was only because the reduced torque would cause the transmission to unlock the torque converter and downshift too often causing more stress (heat) on the transmission. There is no inherent reason not to tow in OD (5th in our 4Runners) if the final drive ratio is low enough to prevent the TC unlocking/downshifting, right?

broc

 

[Redline]

It cost me about $4,000-4,500.00 total, I had a couple other things corrected when the gears were being done. It took about two days for the gears/lockers, the other stuff caused it to run into a third day.

It is generally accepted that overdrive is the weakest gear in the trans, but I still tow with overdrive with my F350 (manual trans, 5th) but try not to really push it up hills in O/D like I used to. But at 125k the ZF trans is still pulling. I'm even more cautious about pulling in overdrive with an automatic, but the size of the load makes a difference.

I wouldn't pull my big 30-ft. Avion 7-8K in overdrive but I will pull the relatively light Chaser in O/D if the engine will pull it. I just came back from a 5-day trip and with 4.88s spent plenty of time in overdrive at highway speeds. I also didn't hesitate to drop the tranny into 4th for the bigger hills. The 4.88s really pull the camping load well with the engine around 3-3,200 RPM.

My Toyota 5-sp A/T won't even go into 5th/overdrive when in low-range, obviously to save 5th gear from the torque.

Redline,
Glad you are happy with your new gears. I am really wanting to do the same, but I'm not sure my wife can live without the truck for that long. What was the total install time and ballpark cost (if you don't mind)? Obviously both will vary by installer, but just curious how long I'd have to rent a car. What break-in procedure did you follow?

Finally, anyone know of a reputable installer in the Austin area? This might be the biggest hurdle for me, as 4x4 shops are fewer around here...

Another general question: I've always heard not to tow in OD. I assumed this was only because the reduced torque would cause the transmission to unlock the torque converter and downshift too often causing more stress (heat) on the transmission. There is no inherent reason not to tow in OD (5th in our 4Runners) if the final drive ratio is low enough to prevent the TC unlocking/downshifting, right?

broc

 

[Redline]

Christmas MPG Update

Over the recent Christmas holiday we drove the 4Runner over the hill (Donner Pass) down to the San Francisco Bay Area because it was snowing. Heading west, mostly downhill we were in moderate snow conditions with light traffic most of the way. For about 50-miles we drove 35-45-MPH (good for economy). When the snow turned to rain at lower elevations speeds were up to 63-65. Filled up in Dixon CA and achieved 18.18 MPG.

Second tank was the rest of the way down to SF, some city driving, down to the Peninsula town of Palo Alto on Dec. 26, and back to Dixon. 14.69 MPG.

Third Tank - Dixon CA back to Northern Nevada in heavy traffic that cost fuel economy - 15.01 MPG.

I had removed my tire swing-away, 20L gas can, Hi-Lift, and shovel before taking this 'car' trip, a total savings of 251-lbs. I'm sure it helped a bit with MPG but I wouldn't be surprised if the impact was minimal, the 4Runner still weighs a lot.

Total trip miles - 608
Trip MPG - 15.96

 

[Redline]

Mellow Highway and 'Normal' MPG

In October I had a four day work week where I used the 4Runner to commute for work (unusual). The route included a little freeway, a little city, and mostly rural highway with a few traffic lights. I really tried to nurse it along, looking farther ahead than usual, light accelerations, etc. but did drive the speed limit (mostly 65 on the highway/freeway).

270.16 miles

17.55 MPG

Tires on the car were Maxxis Bighorn MT in 255/85R16.

A week later I did the same route, didn't drive quite as careful and logged 16.70 MPG.

'Normal' mixed driving:

The six fill-ups after the above data, a combination of mixed driving, freeway, and city errands, including over 100-miles of pulling a small utility trailer (weighs about 1200-lbs empty).

Average was 15.03 MPG

15.26
15.89
14.43
14.88
14.82
14.91

 

[Scott Brady]

Those are very good numbers James. I remember the ARB truck we had, with the roof rack averaged around 11mpg.

 

[Redline]

Maybe you guys drove it harder :sombrero:

I'm happy that trailer pulling has helped me to 'just say no to roof racks' ☺

Was the ARB truck (Tacoma right) re-geared?

Those are very good numbers James. I remember the ARB truck we had, with the roof rack averaged around 11mpg.

 

[tacollie]

I got 11mpg coming back from New Mexico this weekend. 4.88s with the auto seems the way to go.

 

[HMR]

I got 11mpg coming back from New Mexico this weekend. 4.88s with the auto seems the way to go.

11mpg in your Tacoma? Were you towing a trailer?
We just got back from another 2,000 mile trip through the Southwest. With a mix of dirt, snow and 75mph highway we averaged 16.5mpg for the entire trip. 265/75/16 BFG's, stock gears, RTT and a heavy load:

This has been the norm for the last 70,000 miles I've put on the truck.

Redline- Thanks for starting this thread and sharing your data. I'm taking notes!

 

[Redline]

That's a very good average with the higher speed highway driving. The 265/75R16 tire size surely helps.

I have the same question, was the 11MPG towing? Driving very fast?

11mpg in your Tacoma? Were you towing a trailer?
We just got back from another 2,000 mile trip through the Southwest. With a mix of dirt, snow and 75mph highway we averaged 16.5mpg for the entire trip. 265/75/16 BFG's, stock gears, RTT and a heavy load:

This has been the norm for the last 70,000 miles I've put on the truck.

Redline- Thanks for starting this thread and sharing your data. I'm taking notes!

 

[mr.trd]

I am trying to decide the same thing and I swaying to the side of 4.88's. Mainly cause lower will be me more benefit than high. I get about 14-15mpg as is, so it really can't hurt me there, and I want to go to a 305/70R17 in the future anyway. Thanks for all your numbers they have helped me decide!

 

[Redline]

You might get slightly less MPG with 4.88s depends on how you drive, but the difference between 4.88s and 4.56 has got to be small in most applications.

I am trying to decide the same thing and I swaying to the side of 4.88's. Mainly cause lower will be me more benefit than high. I get about 14-15mpg as is, so it really can't hurt me there, and I want to go to a 305/70R17 in the future anyway. Thanks for all your numbers they have helped me decide!

 

[mr.trd]

I might, but even as it is, I usually never drive over 65, just cause any faster and the truck is shifting constantly. Every little incline and every breeze and it kicks down, so I just drive slow. And I use premium fuel, with regular or mid-grade, it is even worse. But the one question that is still getting me, is that I do want to s/c it someday, so with that, would the 4.88's be too low?

 

[heeltoe989]

I might, but even as it is, I usually never drive over 65, just cause any faster and the truck is shifting constantly. Every little incline and every breeze and it kicks down, so I just drive slow. And I use premium fuel, with regular or mid-grade, it is even worse. But the one question that is still getting me, is that I do want to s/c it someday, so with that, would the 4.88's be too low?

I have the SC and I run 456 with 285.70.17 on Walkers. I find the 456 gears with the extra 100hp is plenty of gear for everything. I cruise at 70mph on the highway and sit at 2500 rpm, no gear changes on most hills around here, lots of power for the trailer and trail.