Help with gear and tire MATH

khoopes · 07-24-2008, 12:13 PM

Can someone start me in the right direction with this subject. I have an 88 truck with 22RE, If I run different size tires than factory how do I develop the correct gear ratios for the axles to compensate? I am not talking about anything major, just maybe 31's when the factory was 225/75's. I want to maintain my torque curves on the low end and keep my GAS MILEAGE!

Do larger tires of similar tread design automatically mean lower fuel mileage if you keep the gear ratio constant?

Thanks for any help!

Blizzard · 07-24-2008, 01:03 PM

Do a simple equation.

4.10 are for 29 what X are for 31's. For example.

But as general rule for you gasers is:

31 - 4.56
33 - 4.88
35 - 5.29

David

EWAYota · 07-24-2008, 01:42 PM

Quote:

Originally Posted by Blizzard

Do a simple equation.

4.10 are for 29 what X are for 31's. For example.

But as general rule for you gasers is:

31 - 4.56
33 - 4.88
35 - 5.29

David

X2 on what he said.

terrybo3 · 07-24-2008, 01:59 PM

How will 33's with 4.56 gears work with a V6? What about gas mileage?

tc · 07-24-2008, 02:15 PM

Quote:

Originally Posted by EWAYota

X2 on what he said.

x3 - the rigs that came with 31's stock had 4.56 with the manual tranny and 4.88 with the auto.

Quote:

Originally Posted by terrybo3

How will 33's with 4.56 gears work with a V6? What about gas mileage?

My truck was V6/MT/4.56/31 stock - my opinions of the different combos:

4.56/31 - too low. First was about worthless - by the time you got moving, you were tached out.

4.56/33 - too high. First had some "legs" now, but there was a noticeable loss of pep in 5th. Had to downshift A LOT more. Speedo was DEAD ON to the GPS (<1 miles per hour difference at 70MPH)

4.88/33 - JUST RIGHT. First has some usefulness, and it will hold 5th on rolling terrain.

904_runner · 07-24-2008, 02:21 PM

33's will work with 4.56's i just put some on my truck and i agree with what tc said. I can still use 5th gear in mine though Haven't tried 33's with 4.88's in my rig though.

(i think my 33's are on the smaller size though, maybe 32's)

toyota-erik · 07-24-2008, 03:09 PM

Most of the opinions seem to be pretty close but here's something a little more technical for you.
The formula has all the info you need except your gearing ratios. Note: the numbers will be a little off with a non-lock-up auto tranny.

crolison · 07-24-2008, 03:38 PM

I am going to go 33' and 4.56, until i find an already locked geared front third, then i would regear the rear.

terrybo3 · 07-24-2008, 06:42 PM

That's kinda what I was thinking...4.56 for now with the 33's, and when I find an elocker from a salvage yard with 4.88's, I'll get that and break down and get the 4.88's for the front then. How will that affect gas mileage though?

blueyoda · 07-24-2008, 06:55 PM

My 33's run fine with 4.56. 1st and 2nd are a lot nicer on the street, rpm's are a bit lower on the hiway, gas milage after checking the "real" speed hasn't changed.

axekick · 07-25-2008, 07:45 AM

I ran 33's for about two years on the stock 4.10s. My new 5.29s are much better though. Pretty wound out on the highway but I think it likes it.

surf4runner · 07-25-2008, 01:57 PM

http://www.angelfire.com/fl/procrastination/rear.html

89dlx · 07-25-2008, 02:10 PM

My truck came with 225/75 15's. I put 31X10.50 15's on it. With the 22RE 5-speed it was a dog with 4:10's in it. I had dumptrucks passing me while going up hills. I recently put 4:56's in it and immediate power increase.It's no longer a dog, but I haven't did a fuel mileage check yet.

lil_mule · 07-29-2008, 07:24 AM

I was looking at the Marlin site and their 3rd members only come in either 4.88 or 5.26 would that be overkill for my 81 4cyl w/31's?

tc · 07-29-2008, 10:16 AM

4.88's might not be too bad, especially if you use it offroad. Having the RPM's up will help the carburetor at angles.

Gonna be taching somewhere around 3500 RPM at 70 on the highway though ... no problem for the engine, hell it will love it, but takes some time getting used to the noise!

Plus then you're ready to go to 33's ...

grant526 · 07-29-2008, 12:35 PM

I ran 31's and 4.10's for a couple years. I actually really liked that combo. Now I'm running 33's and the stock 4.10's until I have the money to re gear. It's definitely a DOG at the moment. But it Looks good! lol

If you run 31's you are running about 10% over stock gearing, if you are still running stock 4.10's. Personally, like I mentioned, I really liked that combo. It still had most of the bottom end of stock, but tached a little lower at speed. And it still climbed hills decent. I'm looking at going to 4.88s with my 33's. But now that it's not my daily driver, I'm thinking 5.29's make more sense.

Good Luck!
Grant

lil_mule · 07-29-2008, 02:09 PM

maybe I'll just go with the 33's....the main thing is I want to leave it stock height...I wonder if 33's will fit....

blueyoda · 07-29-2008, 02:32 PM

they fit REAL NICE!!

baseballchamp157 · 07-30-2008, 01:06 PM

man, I have stock 3:73 gears in my 94 with 5in of lift. I push 32/11.50s without a problem. i dont know what yall are talkin about

tc · 07-30-2008, 06:59 PM

Um, no, you obviously don't know what a properly geared vehicle runs like...

a4runnerfreak · 08-02-2008, 04:58 PM

Well, I'm running 31x10.5's on my v6 with an auto tranny, and stock gears are 4.56's, and I'm getting 17-18mph city, 21 highway at 30psi

07-24-2008, 12:13 PM	#1 (permalink)
khoopes Registered User Join Date: Apr 2006 Location: Oklahoma, USA Posts: 95	Help with gear and tire MATH Can someone start me in the right direction with this subject. I have an 88 truck with 22RE, If I run different size tires than factory how do I develop the correct gear ratios for the axles to compensate? I am not talking about anything major, just maybe 31's when the factory was 225/75's. I want to maintain my torque curves on the low end and keep my GAS MILEAGE! Do larger tires of similar tread design automatically mean lower fuel mileage if you keep the gear ratio constant? Thanks for any help! __________________ Kristopher 88 DX 4X4 X-cab 2.4L 5 speed 235/75/15 under restoration. I need a blue radio bezel and interior panels for the extra cab. Does anyone have an nice stock 87 Turbo 4 Runner SR5 w/sunroof for sale??? Previous Rides: 91 4 Runner 4X4 SR5 3.0L Auto 31X10.5 93 Pickup SR5 Xtra-Cab 4X4 3.0L stock 31X10.5 92 Pickup DX Xtra-Cab 4X4 3.0L headers, flowmaster, K&N, 32X11.5

07-24-2008, 01:03 PM	#2 (permalink)
Blizzard Registered User Join Date: Jul 2004 Location: Barcelona (Spain) Posts: 857	Do a simple equation. 4.10 are for 29 what X are for 31's. For example. But as general rule for you gasers is: 31 - 4.56 33 - 4.88 35 - 5.29 David __________________ '94 Toyota 4Runner 3.0 Turbo Diesel Intercooler – Trail-Gear 4'' SAS front, Trail-Gear 5'' rear leaves swap, 35x12.5x15 M/T's and too many things more to write...

07-24-2008, 01:59 PM	#4 (permalink)
terrybo3 Registered User Join Date: Jan 2008 Location: Clearwater, Florida Posts: 107	How will 33's with 4.56 gears work with a V6? What about gas mileage? __________________ ...look at that stock flex!!! :D Model: 1995 4Runner SR5 - Blue/Blue Engine/Performance: 3.0 L V6 3VZE, 5spd. Manual, everything stock so far... Suspension: Stock Tires: 31x10.50 on stock wheels Misc: Extra Power Outlet Mod (3 total outlets), 200W Power Converter Mod(for the laptop), more to come

07-24-2008, 02:21 PM	#6 (permalink)
904_runner Registered User Join Date: Mar 2008 Location: Chico, California Posts: 1,543	33's will work with 4.56's i just put some on my truck and i agree with what tc said. I can still use 5th gear in mine though Haven't tried 33's with 4.88's in my rig though. (i think my 33's are on the smaller size though, maybe 32's) __________________ -Mike 1990 4runner SR5, 3.0 with 253K, 5-speed, 4.56 gears, warn premium hubs, Hella 500's, Rancho 9000's, 33X12.50's trxus mt's, rear lock right, 4" trailmaster lift with lc coils in rear, panhard drop bracket One Day: 3.4 swap and SAS! www.myspace.com/222948743

07-24-2008, 03:09 PM	#7 (permalink)
toyota-erik Registered User Join Date: Jul 2008 Location: M/V Midland & Biwabik MN Posts: 165	Most of the opinions seem to be pretty close but here's something a little more technical for you. The formula has all the info you need except your gearing ratios. Note: the numbers will be a little off with a non-lock-up auto tranny. Attached Thumbnails $help-gear-tire-math-driveshaft_rpm.gif$ __________________ 81 Toyota P/U, 22R with GotPropane kit, wheelbase stretched 5", bobbed box, narrowed tube frame from cab back, full exo, tube doors, Warn 9000i, 36" IROKs,TR bead locks, 4 link front, 3 link rear, Fox 2.0 16" all around. Rear axle is shaved, trussed, V6 3rd, CroMo axles, 4.88, full spool, and disc brakes. Front axle is trussed, HP 3rd, 4.88, 30spline Longfields, and a lunchbox locker. Full hydro Howe desert series race pump(reworked by PSC), CroMo steering arms, 4.7:1 t-case

07-24-2008, 03:38 PM	#8 (permalink)
crolison Registered User Join Date: Mar 2007 Location: knoxville, tn Posts: 1,471	I am going to go 33' and 4.56, until i find an already locked geared front third, then i would regear the rear. __________________ 97 4runner, 2.7 5speed 4wd, 4.556, 255/85/16 Maxxis Bighorns rear diff breather, 4 hella 500's driving, sliders, wilderness rack custom bumper arb locked rear toytec adjustables, ome 891's, bilstein 5125 manual hubs broken front and rear swaybars My Profile

07-24-2008, 06:42 PM	#9 (permalink)
terrybo3 Registered User Join Date: Jan 2008 Location: Clearwater, Florida Posts: 107	That's kinda what I was thinking...4.56 for now with the 33's, and when I find an elocker from a salvage yard with 4.88's, I'll get that and break down and get the 4.88's for the front then. How will that affect gas mileage though? __________________ ...look at that stock flex!!! :D Model: 1995 4Runner SR5 - Blue/Blue Engine/Performance: 3.0 L V6 3VZE, 5spd. Manual, everything stock so far... Suspension: Stock Tires: 31x10.50 on stock wheels Misc: Extra Power Outlet Mod (3 total outlets), 200W Power Converter Mod(for the laptop), more to come

07-24-2008, 06:55 PM	#10 (permalink)
blueyoda Registered User Join Date: Nov 2006 Location: Sudbury ON Canada Posts: 375	My 33's run fine with 4.56. 1st and 2nd are a lot nicer on the street, rpm's are a bit lower on the hiway, gas milage after checking the "real" speed hasn't changed. __________________ -95 3.0 5spd xtncab, 33x10.5 TSL Radial, warn gold hubs, 6" shackles, K&N, isr mod, pioneer deck. bucket seats, 4rnr center console -91 runner 3.0, rancho rs5000, 1.5" rear spring spacers, custom rear trail armour, sony cd/mp3,K&N(FOR SALE) -93 Runner 3.0 (SAS PROJECT) -90 Runner 3.0 parts beast -I live to hear people say "you can't drive there with a truck" It's not a truck, it's a TOYOTA -take your chrome home -ALL TERRAINS are for people who turn around at the first mud hole

07-25-2008, 07:45 AM	#11 (permalink)
axekick Registered User Join Date: Jul 2008 Location: Texas Posts: 86	I ran 33's for about two years on the stock 4.10s. My new 5.29s are much better though. Pretty wound out on the highway but I think it likes it. __________________ '94 Regular Cab Pickup 22re, 5 speed 5.29's (Should've done that a long time ago) Aussie Locker rear, Custom Metal Flatbed. 33X12.5X15 Pro Comp A/Ts 3" Body Lift Fighting Solves Everything... ...except for partial differential equations.

07-25-2008, 02:10 PM	#13 (permalink)
89dlx Registered User Join Date: Oct 2006 Location: Branford, CT. Posts: 898	My truck came with 225/75 15's. I put 31X10.50 15's on it. With the 22RE 5-speed it was a dog with 4:10's in it. I had dumptrucks passing me while going up hills. I recently put 4:56's in it and immediate power increase.It's no longer a dog, but I haven't did a fuel mileage check yet.

07-29-2008, 07:24 AM	#14 (permalink)
lil_mule Registered User Join Date: Jul 2008 Location: NE South Dakota Posts: 15	I was looking at the Marlin site and their 3rd members only come in either 4.88 or 5.26 would that be overkill for my 81 4cyl w/31's?

07-29-2008, 10:16 AM	#15 (permalink)
tc Contributing Member Join Date: Nov 2005 Location: Longmont, CO Posts: 6,586	4.88's might not be too bad, especially if you use it offroad. Having the RPM's up will help the carburetor at angles. Gonna be taching somewhere around 3500 RPM at 70 on the highway though ... no problem for the engine, hell it will love it, but takes some time getting used to the noise! Plus then you're ready to go to 33's ... __________________ Check out www.coTTORA.org to hook up with great Toyota 'wheelin' folks! Current - 93 4Runner: 3VZ 33"x10.50" no lift ARB F/R 96 Impala SS: My own personal cop car Previous - 89 2WD Pickup 22R, Fabtech "Ivan Dan" lift, 31x10.50, IASCA World Finals 4th Place Stop with the mods and get on the trail! Pix at www.4wheelingoh.shutterfly.com/action

07-29-2008, 12:35 PM	#16 (permalink)
grant526 Registered User Join Date: Jan 2008 Location: Sacramento area, Ca Posts: 181	I ran 31's and 4.10's for a couple years. I actually really liked that combo. Now I'm running 33's and the stock 4.10's until I have the money to re gear. It's definitely a DOG at the moment. But it Looks good! lol If you run 31's you are running about 10% over stock gearing, if you are still running stock 4.10's. Personally, like I mentioned, I really liked that combo. It still had most of the bottom end of stock, but tached a little lower at speed. And it still climbed hills decent. I'm looking at going to 4.88s with my 33's. But now that it's not my daily driver, I'm thinking 5.29's make more sense. Good Luck! Grant __________________ '85 Standard Cab 4.5" HD SuperLift Custom Winch bumper 33x12.50 Mud Rovers Lincoln Locked in the rear DD's: '87 XJ and '91 Suzuki DR650s Wheel Responsibly, Don't screw it up for others...

07-29-2008, 02:09 PM	#17 (permalink)
lil_mule Registered User Join Date: Jul 2008 Location: NE South Dakota Posts: 15	maybe I'll just go with the 33's....the main thing is I want to leave it stock height...I wonder if 33's will fit....

07-29-2008, 02:32 PM	#18 (permalink)
blueyoda Registered User Join Date: Nov 2006 Location: Sudbury ON Canada Posts: 375	they fit REAL NICE!! __________________ -95 3.0 5spd xtncab, 33x10.5 TSL Radial, warn gold hubs, 6" shackles, K&N, isr mod, pioneer deck. bucket seats, 4rnr center console -91 runner 3.0, rancho rs5000, 1.5" rear spring spacers, custom rear trail armour, sony cd/mp3,K&N(FOR SALE) -93 Runner 3.0 (SAS PROJECT) -90 Runner 3.0 parts beast -I live to hear people say "you can't drive there with a truck" It's not a truck, it's a TOYOTA -take your chrome home -ALL TERRAINS are for people who turn around at the first mud hole

07-30-2008, 01:06 PM	#19 (permalink)
baseballchamp157 Registered User Join Date: Aug 2007 Location: Ocala National forest FL. Posts: 56	man, I have stock 3:73 gears in my 94 with 5in of lift. I push 32/11.50s without a problem. i dont know what yall are talkin about __________________ BACKWOODS SOUTHERN REBEL! 85 with stock 4:10gears and a 22re 5speed. muddin 33/12.5 procomp M/T and a 3in roughcountry lift...94 pickup with a rebuilt 22r. stock road gears, 5 speed with 2in bodylift and 3in sus. lift. riddin on 32/11.50 baja mickythomsons.

07-30-2008, 06:59 PM	#20 (permalink)
tc Contributing Member Join Date: Nov 2005 Location: Longmont, CO Posts: 6,586	Um, no, you obviously don't know what a properly geared vehicle runs like... __________________ Check out www.coTTORA.org to hook up with great Toyota 'wheelin' folks! Current - 93 4Runner: 3VZ 33"x10.50" no lift ARB F/R 96 Impala SS: My own personal cop car Previous - 89 2WD Pickup 22R, Fabtech "Ivan Dan" lift, 31x10.50, IASCA World Finals 4th Place Stop with the mods and get on the trail! Pix at www.4wheelingoh.shutterfly.com/action