Hey guys need some help, I'm going to change out my rear gears on my truck. I can't decide between 4.10, 4.30 or 4.56 I'm also debating on 33's or 35's but I do a lot of highway and city driving about 65% highway 35% city any suggestions.

 

What gearing and tire size are you starting with and what motor does the truck have?
Are you happy with the performance and fuel milage you get now? You won't get better milage with larger tires and more gearing but you should be able to at least retain the performance.

 

3.55 gears, 255/65R17 tire size and it's a 4.6L, yeah I'm happy with what fuel mileage and performance I have now, if I lose a couple of mpg's I won't be upset I have an S&b cold air intake with SCT tuner, i have NGK iridium ix plugs with accel coils and long tube headers

 

I think for your driving style and tire size, the 4.10's would be the right choice. Especially if you go with 33 inch tires. For 35 inch tires a lower gear would be desirable. I run a metric 285/75-18 that is 34.5" and have 4.56 gears. I like them a lot, but I don't do much high speed freeway driving. Mostly rural roads at 60 mph or so. I have the 5.4L / 9.75" rear end so 4.30 was not an option for me. I wish it was because this would have been perfect for my truck.

 

OK.. I'm of the opinion that 3.73 is the perfect gear ratio for a 4.6 with 30" tires so my suggestion is to go with 4.30 gears, this will produce a little more mechanical advantage with 33" tires than you have now but bigger tires are heavier so that's not a bad idea anyway. Don't forget to recalibrate your speedo after the tire upgrade or you will be driving faster than you realize and that will impact fuel milage.

 

Thanks guys for your suggestions, this will definitely help in my final decision