How much MPG loss is there between those gears?

Off-the-line being the only benefit, people with those gear ratios, please give me you opinions...

THANKS

 

if you are towing a lot, I would run 4.10s for mileage. if not, I would run 3.73s. I have 4.10s currently, and I am going to change to 3.73s in the near future for mileage.

 

I bet about 10%.

 

I have the 4.10's but then again I tow a lot with my truck. Like the gears but if you want to keep the fuel mileage up then 67 mph is about it to keep the RPM's under the 2,000 mark.

 

I have the 3.73 and can get 18-18.5 cruising, A friend of mine has the exact same truck as mine and with the 4.10s he gets 15.5-16 on the same trip and speed. Some of it could be the difference in trucks but I would be that most of it is gearing. I don't pull enough to justify the 4.10s.

 

I have about 96k miles on 3.73, 25k of that is pulling the Fox which is about 7500# or so. I get 19 MPG if I'm not towing and staying close to 65, 17.5 - 18 @ 70 (~2000 RPM), 16.6 - 17 @ 75. For towing, 13 @ 55-60, 12 @ 65, down to 9.5 at speeds I don't wish to discuss .

 

Unless you're planning on running a 35" or larger tire, I would stick with 3.73. MPG will still be bad with larger tires and 4.10's but atleast you'll keep the powerband. If you have 4.10's and never drive faster than 65 you can pretty decent mileage, but if you're like me and are often seen cruising at 75-80 4.10's are going to do dirty things to the pocket book.

 

I have 4.10's with 35" tires.. This setup makes the effective ratio equal to 3.73 with stock tires.

If you're going to get bigger tires.. I would go with the 4.10s due to the less strain it puts on the trans vs. 3.73 with bigger tires.

I get about 20 MPG cruising on flat roads @ 70. (RPM's are right at 1900)

 

I don't tow much but wanted 4.1 because I don't have 4wd/low range for moving around in soft dirt. I love it - it's perfect with the 6spd. My 97 doesn't even have ONE good gear for towing around street corners - 2nd is too slow and 3rd is too high. My 03 has TWO great gears for street corners. The 97 and 03 both get 21 or better - work driving. I drove a 3.73 auto and 3.73 6 spd. The 6 spd was fine but I thought the auto sucked for gearing. I hear the 4.10 auto is good. I've always read there's about 2 mpg drop going to the 4.1. Craig

 

unless you plan to tow in the mountains all the time get the 3:73 i had one truck with the lower ratio and i will not ever have it again. i tow just fine and my trailer weighs 8k by itself and then i'll putt a lot more on it and with a flick of a swithch i can run just as fast as i want to go and still get the mileage

 

I have 4.10s and 315s and think 4.10s are still to low. Maybe once I get to 37s the 4.10s will be ok. I have kept record of every mile driven and every gallon put in the truck. The past 20k miles I have averaged 17.4 mpg with a high of 19.3 and a low of 13.7 (truck and trailer weighed in at 17k).

If I end up staying with 315s you can bet I will go to 3.73s. I want to run 75 to 80 and stay around 2100 rpms.

 

Had one with 3:55s Never again. If towing its 4:10s.

 

ok so if im going to use my truck for pulling 35 foot 5th wheels and other campers for a living what should i do, ill be loaded one way only. im thinking of going 3.73 but my buddy said do 4.11, but im also thinking of a powerbox

 

4.10s ! You'd regret 3.73s 68 mph in high gear up the hill and down the hill.Keeps the Cummins in the sweet spot.

 

I mainly wanted the 4.1 for backing uphill into tight camping spots,soft dirt etc.. If you stay on hard roads and out of the soft RV storage lots with mega RVs I'd get 3.73. Or get 4.1 and put on taller tires if you need too. Craig