Tacoma Dude

Sorry don't mean to hijack the thread but I'm curious - I know nothing about re-gearing so I'm ging to ask while it's somewhat on the topic.

When getting an aftermarket locker - can you regear as an option? Like when you're getting new tires - can you just get a locker with a different ratio? Or is it TOTALLY off?

Excuse my ignorance please!

Tacoma Dude

2001Millrunner:

I just noticed your quote in your sig. Sounds like we're both a bit lost

Mad Chemist

From what I understand (I'm not an expert either), the locker is independent of the differential, when you get a locker you're not changing the gearing in the differential. So, I think Toyota has one electric locker that works with all the different gear ratios.


Read up on this to see how it works:

http://auto.howstuffworks.com/differential8.htm


"The locking differential is useful for serious off-road vehicles. This type of differential has the same parts as an open differential, but adds an electric, pneumatic or hydraulic mechanism to lock the two output pinions together. This mechanism is usually activated manually by switch, and when activated, both wheels will spin at the same speed. If one wheel ends up off the ground, the other wheel won't know or care. Both wheels will continue to spin at the same speed as if nothing had changed."

Birdman

320-335!!! Do you have a 4 cylinder? I have been running 265/70/16 and getting 265 mpg 60/40 highway/city. On an all highway trip I think I squeezed 295 out of it but 320? Granted, I a a bit oif a lead foot. But I am still in disbelief based on the highway figure alone.

rimpainter.com

I run 75's and the power "loss" is significant. Between the black steelies and the 75's, the moment of intertia is annoying with 4.10's and the V6. I dont like it, and I might just switch back to 70's.

TacoBell

I didn't notice any power loss at all on my truck going not only to a 265/75, but from a P to an LT in a D load range. And all that is on my 2.7l engine! My friends even comment on how quick my truck is compared to their V6's. My advice is to lose the 265/70's and go to the 75's. They are easier to find, you have more options, and they just look better.

Darren

Big deal about 320! When mine was stock, the highest I got up to was 379.5. I put in 16.7 gallons on that tank, and the most I've fit in is 20.1 gallons. So, continuing that 22.7 MPG figure, and had I run it empty, I could've gone 77 more miles (456.7)! Those days are LONG GONE, though.

With my 285 muds, I'm still doing better than you with the OEM size, which sounds quite strange to say the least. I can usually make it to the 290/300 mark on the trip meter, which equals out to 310/321 miles with the size difference equation. That's about a 15.5 MPG average.

On another note, Alan (HaveBlue) claims to get upwards of 27 MPG with that fuel atomizer thing--and he's supercharged!

Birdman

Well......I've got an SR5 V6 5speed with 4.10's and just ordered 285/75/16s so I hope the loss is bearable. I was originally planning on moving from the 265/70/16s to a 265/75/16, but In talking with the chief mechanic at the shop who has a 1996 4runner said wouldn't be a big deal. I'm still a bit unsure but will regear if I have to...... If I do end up regearing, I will likely toss in a rear ARB Air Locker........$$$$$ Bling bling!

Birdman

This has me a bit worried but it has been this way since the day I bought it, used with 60K on it. All highway miles. I wonder if it has anything to do with altitude. I'm at sea level. If anything I would think I'd get better gas mileage. BTW, my tank only takes 18.5 gallons and I don't think I've ever put in more than 17gals. My gauge was scraping the bottom at that point and I was sweating. Now I gotta break out the recipts and figure this crap out.

chuckd

Okay, stupid question time, are 265/75 16s 32" tires? Just curious.

Darren

I suppose it depends on which brand. As I said on this thread over a year ago, 265/75 MT/R's are 31", but sit at 30" on the truck. The 285's are exactly 2" taller.

rimpainter.com

Now I'm confused. I thought the second number referred to the sidewall height, not the first. The first is width isn't it?

Maybe Darren just worded that last post funny, or maybe its just me.

Darren

In theory, lower altitude should equal worse mileage as there's more air getting in the mix. However, the reduced loss of power (equal to a full supercharger effect where I'm at) often means more downshifting. So who knows?!

I have an 18.5 gallon tank as well, as do all 3rd Gens, but I've put 20 in on a few occasions, topping it out, of course.

Darren

You're correct on both accounts. What did I say that was funny?! I just listed the overall height of the tire.

Birdman

Assuming you have 16" rims, the math works like this. Taken directly from the TireRack Tech page and modified for your dimensions:

The first number is the width of the tire in millimeters, measured from sidewall to sidewall. To convert to inches, divide by 25.4 In the example above, the width is 185mm or 7.28".

The second number is the aspect ratio. This is a ratio of sidewall height to width. In the example above, the tire is 7.28" wide, multiply that by the aspect ratio to find the height of one sidewall. In this case, 185x0.60=111mm or 7.28"x0.60=4.36".

The last number is the diameter of the wheel in inches.

To figure the outside diameter of a tire, take the sidewall height and multiply by 2,(remember that the diameter is made up of 2 sidewalls, the one above the wheel, and the one below the wheel) and add the diameter of the wheel to get your answer.


Width x Aspect Ratio = Section Height x 2 = Combined Section Height + Wheel Diameter = Tire Diameter

Examples:

265/70/16
265mm x .70 = 185.mm x 2 = 371mm + 406.4mm(16") = 774.4mm / 25.4 = 30.488" or 31'ish"

265/75/16
265mm x .75 = 198.75mm x 2 = 397.5mm + 406.4mm(16") = 803.9mm / 25.4 = 31.649" or 32"

285/75/16
285mm * .75 = 213.75mm x 2 = 427.5mm + 406.4mm(16") = 833.9 / 25.4 = 32.83" or 33"

rimpainter.com

That helps, thanks.