---

Register Log In 4x4Wire TrailTalk Forums Jeep Talk What Gears for 33" tire and Auto Trans? Forums User List Calendar Active Threads Search Forum Help

Previous Thread Next Thread Print Thread Rate Thread Page 1 of 3 1 2 3 What Gears for 33" tire and Auto Trans? #639613 08/22/05 10:36 PM Joined: May 2001 Posts: 697 Chandler, AZ USA A AZPetrak OP Rock Warrior Dropping my Jeep off tomorrow, currently has 3.07:1 diff gears - getting ARB front, Aussie locker rear installed and diffs re-geared. My calculations say with 4.11 gears at 69MPH I will be just over 2900 RPM, which is high, with 3.73:1 gear at 69MPH I would be around 2600 RPM which is reasonable. Should I go with the 4.11 gear and put up with the high RPMs? Or go with 3.73:1 and have a little better highway RPMs? This is not a DD but will be driven on highways for fun and to get to trails. 2007 4x4 Tacoma Dbl Cab with TDR and rear locker - stock for now 2001 Wrangler Sport - sold 1998 Rodeo S 4x4 - traded in Re: What Gears for 33" tire and Auto Trans? [Re: AZPetrak] #639614 08/22/05 10:48 PM Joined: Mar 2004 Posts: 2,398 Mississippi JeePete Body Damage is Cool With an auto I'd go for the 3.73's, assuming your calculations are correct. <img src="/forums/images/graemlins/cheers.gif" alt="" /> Freedom Off Road Re: What Gears for 33" tire and Auto Trans? [Re: JeePete] #639615 08/22/05 10:51 PM Joined: Oct 2003 Posts: 534 San Antonio, TX R RockJock Rock Warrior And i think you will be happier with 4.11's <img src="/forums/images/graemlins/lol.gif" alt="" /> Re: What Gears for 33" tire and Auto Trans? [Re: AZPetrak] #639616 08/22/05 10:55 PM Anonymous Unregistered 3.73's are the right gear for the math. I'm running 3.73's (was 3.07's) and 31's and I pull about 2600-2800 RPM at 70 MPH. I'm getting about 20 MPG out of my jeep.. 33's with 3.73's would drop the RPM's to near stock levels.... That said, 3.73's and 31's with low-range is a very nice low gear for the trails. If I were you I would go with the 4.11's and 33's. It will be like no OD, you won't be taxing the motor at 70, but it won't be the most fuel efficient possible. You will have nice low gears for off-roading and towing which is very nice. Re: What Gears for 33" tire and Auto Trans? #639617 08/22/05 11:08 PM Joined: May 2001 Posts: 697 Chandler, AZ USA A AZPetrak OP Rock Warrior If you only look at the tire size change, 3.73 gears would get you back to stock ratio with 35 inch tires, so with 33s it would still be a slight higher gear that stock. 2007 4x4 Tacoma Dbl Cab with TDR and rear locker - stock for now 2001 Wrangler Sport - sold 1998 Rodeo S 4x4 - traded in Re: What Gears for 33" tire and Auto Trans? [Re: AZPetrak] #639618 08/22/05 11:14 PM Anonymous Unregistered I calculate closer to 34's... Since you won't be hitting the highway to much, the lower gearing is really nice off-road. plus with 4.11's you could run 33's or 35's. Re: What Gears for 33" tire and Auto Trans? [Re: AZPetrak] #639619 08/22/05 11:30 PM Joined: Oct 2003 Posts: 7,768 Central Texas BigJim Web Wheeler You MUST remember that the taller tires are HARDER to turn! So with the same rpm as smaller diameter tires you will have your foot in it all the time.. This will lower the vacuum and cause the POWER system to come into play much more often.. As a standard you will need more rpm at ANY speed with taller tires than with stock tires. Go with the 4;11'S. <img src="/forums/images/graemlins/smile.gif" alt="" /> Big Jim <img src="/forums/images/graemlins/pfft.gif" alt="" /> professional bovine relocation specialist Re: What Gears for 33" tire and Auto Trans? [Re: BigJim] #639620 08/22/05 11:42 PM Anonymous Unregistered Quote So with the same rpm as smaller diameter tires you will have your foot in it all the time.. The rolling friction is no that much higher. The heavier tire will mean it take more force to accelerate the tire, but not hold it at a given speed. Quote This will lower the vacuum and cause the POWER system to come into play much more often.. TJ's don't have carb's, so no power system. The nice thing about EFI is a more linear fuel curve, so it will be dumping proportional amounts of fuel in. Re: What Gears for 33" tire and Auto Trans? [Re: BigJim] #639621 08/22/05 11:45 PM Joined: Oct 2003 Posts: 534 San Antonio, TX R RockJock Rock Warrior What are you 2 using as the stock tire size? 27" and I get 3.75 28" and I get 3.62 I would still go with 4.10's and I figure you will be running around 2900 rpms @ 65 - 70 MPH and that sound good to me. If you ever pull any trailers you will be even happier you have 4.10's. <img src="/forums/images/graemlins/cheers.gif" alt="" /> Re: What Gears for 33" tire and Auto Trans? #639622 08/23/05 12:12 AM Joined: Oct 2003 Posts: 7,768 Central Texas BigJim Web Wheeler Sunder Disregarding the tire itself and thinking about the LOAD on the axel at speed.. Why would you expect the same rpm to move the vehicle forward with the same effort? Is that not a power system? Surely with less vac the engine needs a higher fuel to air ratio and retarded timing.. Are we disagreeing? <img src="/forums/images/graemlins/smile.gif" alt="" /> Big Jim <img src="/forums/images/graemlins/smile.gif" alt="" /> professional bovine relocation specialist Page 1 of 3 1 2 3 Moderated by  4x4Wire  Hop To Mitsubishi Forums ------  Mitsubishi 4x4 and SUV Tech  Mitsubishi Diesels  Mitsubishi ArchiveToyota Forums ------  Early Toyota Trucks  Toyota 4Runner, FJ Cruiser &...  T100 & Tundra Forum  Tacoma Forum  Toyota Tech ArchiveJeep Forums ------  Jeep Talk  Jeep TechIsuzu Forums ------  Isuzu 4x4 & SUV Talk  Isuzu 4x4 & SUV Tech  Isuzu DieselsKia Forums ------  Kia Talk  Kia Sportage & Sorento TechOff Topic Chat ------  4x4 Gallery  Off-Topic Chat  Recreational Access & Land ...  Politics4xForums ------  Outdoor Gear  General 4x4 Discussion  Tools and Fabrication  General Communications  Amateur Radio  GPS and MapsParts Bin ------  Private Party - Garage Sale  Private Party - Items wanted  Vendors, Hot Deals, Group Buys4x4Wire Back Yard ------  Suzuki Forum  AZ Crawler Crew  Cal-Nev Crew  General Ford 4x4 & SUV Forum  General Dodge 4x4 & SUV Forum  General Chevy 4x4 & SUV ForumFeedback & Testing ------  Problems, Questions, Suggestions4x4Wire Staff ------  Forum Moderators  Problem Threads Print Thread Switch to Threaded Mode 5 Excellent 4 Good 3 Average 2 Bad 1 Terrible View Profile Private Message Follow User Forum Posts View Profile Private Message Follow User Forum Posts View Profile Private Message Follow User Forum Posts View Profile Private Message Follow User Forum Posts View Profile Private Message Follow User Forum Posts View Profile Private Message Follow User Forum Posts View Profile Private Message Follow User Forum Posts

Default Style 4x4-lt-blue 4x4-new Forum Rules · Mark All Read Contact Us · 4x4Wire TrailTalk

OutdoorWire, 4x4Wire, JeepWire, TrailTalk, MUIRNet-News, and 4x4Voice are all trademarks and publications of OutdoorWire, Inc. and MUIRNet Consulting.
Copyright (c) 1999-2019 OutdoorWire, Inc and MUIRNet Consulting - All Rights Reserved, no part of this publication may be reproduced in any form without express written permission
You may link freely to this site, but no further use is allowed without the express written permission of the owner of this material.
All corporate trademarks are the property of their respective owners.