tblrklakemo

The factory brakes on 20" rim equipped trucks are just fine. They have been equipping and selling them that way for yrs. I would suspect a particular issue with his trucks breaks. I have wide 18's and fat rubber that I bet has more rotating mass than 20's and skinnier rubber. I have pulled 7500+/- for 2.5 yrs now and not one break issue in 33k miles. Im not slamming on the breaks but i have had a couple of close calls and they stopped my in time. My v-max has been getting a computer calculated rolling average of 13.2-13.8 mpg. Around town its like 8-9 mpg in stop and go. You will be fine with a stock truck. One thing on the avalanche.....they bed is too narrow to do most full size truck chores unless you have a utility trailer. A golf carts wheels etc just wont clear the bed covers sliding rail. Get the full size quad cab short bed. Deminsionaly outside about the same, but quite a bit more usable bed room. You cannot light up the tires on any stock GM truck w/o powerbreaking 'em or finding a wet or sandy patch.

BUIZILLA

I've had 3, and my brother has had/have 3, all 5.3's, all have/had 3.73 or 4.10 gears... all 6 equaled or bettered the 15 mpg avg numbers... my bro's 07 Tahoe gets over 20 on the road all day long... my last 5.3 CC shorty got right at 19.5 at 78 mph.


ymmv

tblrklakemo

those are great numbers....when you reset your computer what do you get around town?

BRET

I just telling you what my computer readout says. Maybe its off, but I do most of my driving on the highway. Last summer was just afer I broke it in and havn't seen it since. Mine gets better mileage than my brothers (5.3) 07 Avalance. Maybe I got a freak motor.

Knot 4 Me

Brakes are working as designed. Keep in mind the further out from the hub you place the weight, the bigger an issue this becomes. 20's place the weight out further than 18's. Also, look into when GM started offering 20's as optional equipment on their 1/2 ton trucks and SUV's.

Knot 4 Me

You cannot go off the DIC. You have to hand-calculate your numbers over more than just one tank of fuel. The DIC's are usually like boat speedometers...a little happy.

tblrklakemo

I would bet that total wheel and tire weight given the current CAD designed factory alloy wheels GM has would probably be about the same regardless of 17-20's. They probably are mindful enough when designing them to keep most of the mass as close to the hub as possible if they are going to bump rim size up. I dont think they would offer, from the factory, a wheel that dramatically reduced stopping distance or break life. Just a guess. Hell, everybody has 20's now as OEM stuff.

Canada Jeff

2004 Chevy SS had the first 20's I believe. I had one, brakes were fine, but I couldn't stop fast enough for a dam deer. hit it with the truck just 2 weeks old.

Canada Jeff

The truck I'm looking at is an 2007, ext cab, short box, 5.8 feet or something. factory 20's, LTZ, with the power max option.

Jupiter Sunsation

Brakes on my 03 108K mile 2500 CC DD are original with 75% local miles and probably 10K in highway towing my 32 Sunsation. I would bet I have another 25K in meat left on the pads.

My 4 other trucks (all GMC from 4.3s to 5.3s) need pads at 40-50K miles but that is with employees driving the tires off them I am sure!