Foxracing

I bought an new '07 Silverado ext cab with 5.3l , 2 wd a couple of weeks ago. So far I'm not impressed with my new purchase. The '04 Suburban 5.3l, 4wd that I traded in had lots more power, at times I could have sworn that it had a 6.0l in it when pulling trailer loaded with atvs. The new truck can't even spin the rear tires unless it's wetout. Now I didn't buy it to smoke the tires, but wonder if they sold me a truck with a 4.8, the vin shows the code for 5.3l??? When pulling the trailer, it seems to down shift alot compared to the Suburban which weighs considerally more ( trailer loaded no differently). I've own lots of Chevy trucks, and seem to be getting less. The '96 reg cab I had with a 350 was way better for power and fuel mileage. Is there any way to know for sure about it being a 5.3l vs a 4.8???

Fireguy8

I`ve got a 2000 Suburban with the 5.3, towing, 3.73`sand my 2007 Silverrado LTZ w the 3.73`s and the 5.3 no doubt is much better power wise and you can feel the difference. I even have a few mods on the Burb and the new truck is still better.

Intruder

My '02 Silverado had a 3.73 rear end. My '05 CrewCab has 3.41 rear gears. I can sure feel the difference in grunt, but highway mileage is a little better.

What rear gears did you have in old ride and do you have in new? That may be the difference!

engine2

I agree with the posters here. There is a noticeable difference between the available gear ratios with the same engine. Especially on acceleration.

Foxracing

All of my trucks, and the last Suburban(except a '02 4wd that had 4.11) have had 3.73 gears and except for the aforementioned '96, they have all had the 5.3L motors. The only difference has been whether they have had 2wd or 4wd, 2wd trucks are hard to get around here. Dealers and buyers seem to think they need 4wd because of the snow, ha. I really like the truck, but have been unimpressed with the power. I've been pulling the same trailer with all of the vehicles (well maintained trailer). Really wonder about motor size, runs fine, no hesitation, no stumbling, just not the power I'm used to. My old '04 4wd Suburban was heavier and got bad fuel mileage (13-14mpg), but at least felt like it had more pep. The new truck doesn't seem to be getting that great on mileage neither tho I haven't checked it yet, I usually wait till I get 6,000 miles before bothering to check that out.

IAfarmer

I went from an 8.1L to the 5.3. So far, I am happy as the power is there when I need it. This truck is no race winner, but it isn't that bad.

I used to pull with an 86 Dodge that had a carbed 318. Now that was gutless.

2007 Lt1/5.3/3.73

I bought the new body style extended cab short bed siverado, for a every day driver and to pull my camper, I ordered the truck with the gas 5.3 litre a.f.m, the larger 3.73 rear gears and the tow package, the truck has plenty of power and pulls my 18ft toyhauler, which weighs 4500# empty and gross weight of 8000# just fine, as far as smoking the tires, the traction control will keep that from happening! I bet you have the smaller v8 or the smaller rear gear because my truck as equipt is rated at towing 8000#, good luck!

MalibuMaxxSS

open the hood and look ate hte sticker on the fan shroud it says there what engine you have.......or look at the *** end ALLL 5.3 should come with a trailer hitch and tranny cooler....maybe it has 3.42 LOL...that would suck for towing...why people buy trucks with these gears I dont knw, a good headwind will downshift them....and for towing they absolutely suck....

Foxracing

As per tags, truck is the same as previous vehicle. Short of pulling the cover off the rear axle, I have to go by the paperwork that it's a 3.73. All my two wd's have had traction control.

The only sticker on the fan shroud deals with refridgent, sticker on air box claims 5.3, but stickers mean nothing compared to identification through serial numbers (Checked SN already) or casting marks on enginge block which is what I was hoping to get from this post.

Truck seems to be settling in with more miles. First time out with trailer, down shifting like you wouldn't believe, slightest head wind or small hill had it down shift and running at about 3,00rpm. Last pull with trailer, not as much downshifting, found there's a small window of space where truck will go out of overdrive (2,200rpm), but just before downshifting again. Find that I have some control with throttle to maintain speed on upgrades as long as they aren't very large once kicked out of overdrive. Am taking it on a small trip this next weekend, will see if more miles will help. Never had a new truck (have had 7 of them) that needed such an extended break in period. Usually they are never better then when they were brand new.

MalibuMaxxSS

giet me the Vin and I will tell you what it is....If its new the sticker will tell you what it is, it has a 5.3, weither it has 3.73 or 3.42 cant tell ya, unless I have the Vin...if its 3.42 this will explain all your worries of underpowered...

Also when pulling push your tow/haul button on the end of the shifter, this will change your shift points in the tranny, and give you more bottom end, and you may find it shifts better for you, it will shift harder for sure..