KC_kid

iTrader: (5)

Another gear poll. I've been reading about this since I bought my truck since I knew it would require a gear change one day. I've read a ton but still can't decide between 3.73 & 4.11.

My goals are to increase gas mileage (both city & hwy) while improving drivability and performance fun factor.

Truck is a 2011 CCSB 4x4 with 5.3 LC9, 6speed, 3.08 gears and 275/55 on factory chrome clad 20's. Right now I have 4" PVC intake & BB tune, future holds headers and hopefully TVS1900, no cam or stall. I travel 80% city 20% hwy and my highway trips are 200 miles thru the flint hills of KS, long graded hills and always windy. No towing. I'll be driving this truck for many, many years and it could be our family hauler for highway trips to grandma’s house, so I need to it be manageable on the highway. This is going to be expensive so I only got one shot!

I want the 4.11 but the only fear I have is 75 MPH cruising RPM. Gear calculator tells me the 4.11s at 75 and 31.9" tire will get me 2175 RPM. 3.73 = 1974 RPM.

The poll, 3.73 or 4.11 and is 2175 cruising RPM a big deal? Should I go for the gear??

RS/SS 4.8

iTrader: (13)

If its the hills that got u worried do 4.10 and dont look back. There was a similar question asked a few days ago and like 99% said to do the 4.10 swap.

2000chevysilverado

iTrader: (11)

Id say 373 over 410s for gas mileage wise. Youll still have good power as well. I had 410s in my 5.3. S10 got terrible mileage switched to 373s gas mileage was so much better. As of course its ur chioce

KC_kid

iTrader: (5)

A couple things different than your 410 setup is my 6th gear being 0.67 instead of the 4L60e 0.70, if thats what you had. And my 32" tires. I don't know what your setup was though.

I am wondering how gas mileage would compare between the 2, given only 200rpm difference at 75mph.

graysilverado5.3

iTrader: (4)

I went with 4.56s with my 33's. Gas mileage went up 1-2mpg both in the city and hwy compared to the stock 3.42s truck was a turd. I say go 4.11s and don't look back.

2000chevysilverado

iTrader: (11)

Im just thinkn of gas mileage for years down the road. Yes mybold setup would be complety different. But thats y were here. I would do something you want the 411s would be your best choice and you wouldn't second geuss it down the road

KC_kid

iTrader: (5)

No more comments on 2175rpm at cruising speed?? Hurt mileage or no big deal?

oakley6575

iTrader: (5)

I think you are splitting hairs over 200rpm. Obviously you will use less fuel when dropping 200 rpm but it all depends on how you drive, where you drive, ect.

james8997

I'm gonna go against the current here

200 rpms in this case might actually increase mpg buy a hair, your turning slight more rpms, but the engine is working less to do the same amount of work. 4.10s am don't look back. I DD my 97 with 4.10s, 75 put my at 2450, didn't mind it at all

KC_kid

iTrader: (5)

does a future tvs1900 change things here? I'm leaning toward 411s but curious if the SC factors into the decision..