I tow a 26 foot tt, with a quad and dirtbike in the bed. The tt weighs right about 5000 loaded. I have 285/70/17 tires right now with 3.55 gears. If I were to regear to 4.10s how significantly would that change my cruising rpms. I know that it would make the truck work less hard but how would it affect overall mileage. My next tires may be a little larger, either 285/75/17 or 315/70/17. So would 4.56 be better. Just seeing people's opinions. It towed fine last weekend but it was a relatively flat trip. Mountain trips will have to wait till summer. Or is there a chart that explains this? [IMG][/IMG]

 

There are gear calculators all over. Plug in your specs and it'll give you mph or rpms depending on what you are looking for.

Right now, you probably pull around 2200 rpms going 60 mph in 3rd gear.

With 4.10's, you'll be pulling around 2500 rpms. With 4.56's you'll pull around 2700.

Now, you maybe able to run in OD with the lower gears??

Give and take when you want the taller tires..

Nice rig BTW...

Mitch

 

Thanks and I will Google the charts to check it out. I see your truck has done good for a long time. Hope mine holds up that well.
U have a link for me?

 

I went here last night.

http://www.rocky-road.com/calculator.html

It's got other calculators too. For the trans ratio's, you want to use 1 for the trans case ratio and you would use 1 for your 3rd or 1:1 gear. .7 for OD in general... Of course, if you know your exact transmission gear ratio's, you would use them.. The 6 speeds have totally different transmission gear ratios from the 4 speeds for the most part.

Mitch

 

yes you can, i pull a pioneer 22t6 which is ~6800lbs fully loaded and can run O/D most of the time with my 285/75/17 and 4.56:1 gears. granted my mod list is probably more substantial however.

best thing you can ever do is get a quality tow tune from a good tuner *cough* PHP *cough*, that alone will make a notable difference in how it handles shifting.

 

Yeah I have intake, exhaust and programmer for now. Diablosport predator. What cruising rpm are u at around 70 or 75 mph? I drive 40 miles roundtrip to work 4 days a week so I don't want to go too low of gearing. What improvements did u see with the efan? Temp drop, mileage and/or power improvements? And do u like that tire size? Personally not a fan of tires sticking out too far so I think that size would be great.

 

personally not a fan of diablos "canned" tunes. at 70-75 i turn ~2200rpms with only 15-20%throttle according to my gryphon and avg 15-16 mpg mixed. efans gave slightly better throttle response and do help with milage (.5-1.5mpg) and also runs slightly cooler with low temp t-stat. tires i have are awesome Buckshot XMT mudder with 50k miles and still have over half the tread left, but i also have them on 2"wheel spacers cuz i like the wide look


BTW full list of mods: Airaid intake, longtube headers, off road y pipe, efans, PHP gryphon, 4.56 gears, BTS tranny rebuild. so your experience may not be exactly like mine due to every truck reacting to mods differently

 

I'm a fan of the "canned tune" for now as it corrects the lean issue caused by my k&n cai and does add quite a few things. I may end up sending to a third party eventually to add custom tunes but for now it has helped. Saw some for 75 per tune online from a reputable source. I thought it was very strange that it didn't even have a canned tow tune. That was a shock to me, but it was one of the only ones to have canned tunes for multiple cai. Yeah I am a ways away from new tires so I am just seeing how much to save for tires and gears at the same time. May end up with 4.10s and the 285/75/17 Terra grapplers. Not bad cruising rpm at all and I'm sure u have lots of low end grunt. Thanks for the info.

 

4.56 without question.