4.88 vs. 4.56 in a 2006

[Redline]

4.88s Win!

Saving less than 200-RPM to go with the 4.56s for a "possible" fuel economy and engine noise benefit lost out to the known performance advantages of the lower gears. Low end torque, pulling power, and a very good crawl ratio will all be better with the 4.88s. The gears and lockers have been ordered. If the parts arrive next week I hope to schedule the job for the following week! :wings:

When the little V8 4Runner was a stock lightweight it would get-up-and-GO if I put my foot in it. With the new gears I'm hoping that I might have to stop calling it the Mall Crawler and fondly refer to it as my Rocket 88. We shall see :roost:

 

[p1michaud]

Excellent choice

The gears and lockers have been ordered. If the parts arrive next week I hope to schedule the job for the following week! :wings:

I have been secretly hoping you would go the 4.88 route. I know that Mr. Brady has never regretted his decision to go to 5.29 gears in the Tacoma. With your added weight and towing duites I am sure you won't regret your decision! :sombrero:

Have you selected a gear shop/installer?

Well done. :bowdown:

 

[DaveInDenver]

That's awesome! I think you'll be happy with the choice. I don't regret going with 5.29 gears in my truck at all.

 

[Redline]

Well Dave, from one Imelda to another, we have to have the torque to motivate our shoes up the mountains

That's awesome! I think you'll be happy with the choice. I don't regret going with 5.29 gears in my truck at all.

 

[Redline]

Thanks for secretly pulling for the 4.88s, our good Truckma (carma for trucks) must have helped make the decision more obvious.

Everyone's input was valuable, but Scott's response of how simple and obvious the choice was stuck a cord. Sometime it takes others to tell you what you already know to believe it yourself. Weight, mountains, altitude, and towing... what is there to decide.

Though it wasn't part of my decision this time, I often like to be a little different so going with 4.88s when it seems that many people want 4.56s for the new Tacos/FJC/4Runner suits me.

I have a buddy with a 1996 F350 Power Stroke like mine, we purchased them at almost the same time. Most of these trucks were made with 4.10 gears for the pulling/towing torque. He specifically ordered his with 3.54 looking for more MPG and lower RPM at faster road speeds. He drives faster than I, tows less and is still happy with his decision. I do more off-highway travel, tow more, and want the truck to pull as much as possible, even if it 'might' get a couple MPG less. And after the first set of stock 235/85 tires wore out I went to 255/85 33-in tires. I too am still happy with my decision to go with the lower gears, though it means some pretty high RPM at 75-80 with this diesel, I don't usually drive it up there.

The Install Shop:

I have a local 4x4 shop that I trust to do the jobs I can't or don't want to tackle. They did the 4.88 gears in my '05 Rubicon and a new clutch and flywheel in the F350. The owner still runs the shop, and he has one tech that has been with him for about 18-years who specializes in gearing/drivetrain stuff. They are not the least expensive in town but they have a good reputation.

Though I was planning to do some of the install (wring/switches/plumbing) myself I'm going to have them do this part of the job too for only a couple more hours labor. Having it be a turn-key installation has some appeal, if something isn't working, its on them to fix it.

I have been secretly hoping you would go the 4.88 route. I know that Mr. Brady has never regretted his decision to go to 5.29 gears in the Tacoma. With your added weight and towing duites I am sure you won't regret your decision! :sombrero:

Have you selected a gear shop/installer?

Well done. :bowdown:

 

[Redline]

RPM noise/mountain test

This was not a full MPG test as it was not on my relatively flat freeway circuit where I can compare previous data, but I did run up and down my familiar rolling mountain freeway in 4th/direct with the stock 3.73 gears. Final drive ratio is of course, 3.73. After the 4.88s are installed my overall final drive ratio in overdrive will be 3.49 (0.716 x 4.88).

I made a short mountain loop drive on I-80 from Reno, NV to Truckee, CA. Mostly uphill there, mostly down hill back. From about 4,800 to 5,800. Speeds were 65-75, mostly around 70. But the RPM I was running 2500-2600+ will yield a slightly faster road speed, about 75-MPH with the 4.88s.

From watching the stock MPG computer display my guess at this point is that empty fuel economy ‘may’ be slightly lower with the 4.88s in overdrive simply because on the downhill sections I will not have the extremely tall 2.76:1 final drive (0.716 x 3.73) ratio available to almost coast down the hills. But it will really depend on the uphill sections because hill climbing performance will be so much better that I will not lose as much speed or have to put my foot into it if I want to maintain a decent speed. The PCM/MPG display lost a few tenths of MPG going up, but I gained them going back down.

I can barely hear the engine over the MT tires while in direct but it is not annoying at all. Again the tire noise is much louder than the engine. With quiet all-terrain tires I will likely be able to hear the engine more clearly, but I think it won't be annoying. The 4Runner will likely still be the quietest vehicle I won (by far) compared to the '96 F350 Power Stroke or our 2000 VW Golf TDI.

 

[tdesanto]

:lurk:

James, even I can't wait to hear how this comes out. I'm living vicariously through you until I can get all the same work done on my truck.

I'm waiting to hear back from ARB as to when they plan to release the rear locker for the gen III Monteros. I'm hearing from the Australian boards I'm on that it's due down there this summer.

Good luck with the install.

TD

 

[Redline]

Thanks Tony, we shall see if I can get the job done as soon as I want...

:lurk:

James, even I can't wait to hear how this comes out. I'm living vicariously through you until I can get all the same work done on my truck.

I'm waiting to hear back from ARB as to when they plan to release the rear locker for the gen III Monteros. I'm hearing from the Australian boards I'm on that it's due down there this summer.

Good luck with the install.

TD

 

[slooowr6]

:lurk: looking forward to hear your impression on the 4.88!

 

[24HOURSOFNEVADA]

Sometime it takes others to tell you what you already know to believe it yourself.
/QUOTE]

There you go, Right there. you've done the math...the research and the numbers. Run with it. Next thing you know, I will be swapping for 4.88's

 

[DaveInDenver]

Well Dave, from one Imelda to another, we have to have the torque to motivate our shoes up the mountains

You're not kidding. My lovely Imelda went shopping about a couple of weeks ago and ended up with some of the last old style BFG 33x10.50 MT KM tires. She's so picky on what she wants and it took the guy at the tire shop a couple of weeks to source all 5. The 33x10.50 size is backordered, probably due to the KM2 coming out this fall. Every time I shop for 33x9.50 or 10.50 tires, BFG always seems to be in short supply, I simply don't understand why Goodyear, Yokohama, Cooper or someone else doesn't offer something tall and skinny. I guess it's all you guys with the 16" and 17" tires, so not many knuckleheads still running 15" rims.

 

[Redline]

We will test mine then I bet you will be more than ready.

4.88s, all the better for us to travel and compete with :rally_guys:

Sometime it takes others to tell you what you already know to believe it yourself.
/QUOTE]

There you go, Right there. you've done the math...the research and the numbers. Run with it. Next thing you know, I will be swapping for 4.88's

 

[jim65wagon]

anything new to report, James?

 

[lionsbreath]

Here is a great cal. for the gearing question you are asking.
http://www.4lo.com/calc/geartire.htm

 

[Redline]

Thanks for sharing.

http://www.izook.com/gearcalc.htm

I like and have been using the above calculators.

I bet I've done over 100 calculations of various rations, speeds, etc.

Here is a great cal. for the gearing question you are asking.
http://www.4lo.com/calc/geartire.htm