4.8L over 5.3L Vortec
 

I am looking at buying a truck that looks to be a pretty good deal but only has the 4.8L in it (2003 Chevy 1500 Z71 Ext) and not the 5.3L. I dont tow my boat very much (87 28' Saber roughly 7,000lbs) but how much of a dog is the 4.8? It does have a superchip in it and also the K&N cold air intake sys.

Any comments would be appreciated. THANKS

Never towed with either but owned a 5.3 1500 work truck with the factory tow package (listed to tow 8500lbs) that struggled to pull a 32 Sunsation on a triple axle trailer. Boat is 6600lbs dry, plus fuel/ trailer. After a 3 mile ride to a gas station I never hooked that combo up again.
The last loaner I got was a 4.8 1500 Crew that burned rubber around the block. I actually thought it was a 5.3 until checking under the hood to see it was a 4.8.

I liked both the 4.8 and 5.3 enough to buy either if the deal was right but towing that boat may be an issue for you.

That is what i was thinking. I have a 2002 F250 with a powerstoke from work that i use when i go for any long trip with the boat but would be using this pickup with the 4.8 around town and to and from the gas station. What i was really trying to figure was the difference in everyday driving, which you say it very comperable? Thanks, MIKE

Those trucks are geared for fuel mileage, but there was an optional 4.10 rear end that allowed them to be an ok tow vehicle.

With the weight your towing I would opt for a 5.3L. The 4.8 was a fuel milage attempt. I doubt you would be happy even if it had 4.10 gears. I had a 1/2 ton 5.3 with 4.10, now that was great at towing a 6000LB boat. Wasnt great on milage on the highway.

Do you carry stuff with it in the bed? Father in law bought the 4.8L to save on fuel. He ended up trading it in to get the bigger motor.
1) MPG's were not there
2) Transmission would down shift to climb interstate overpasses, drives people nuts.

Granted he is a carpenter and he was hauling 700-1000lbs of gear everyday, but he dumped for the 5.3 and is getting better mpg's.

Jim

It has a chip and a cold air intake already? That should answer your question! Not enough beans

5.3 with a 4.10 is what you will need for 7K #'s. Or better yet get a 8.1 or a Duramax and don't worry about the tow #'s.

Mike you will not notice the difference driving both around town. I think a few responses are confusing the 4.3 with the 4.8 motors. The 4.8 and 5.3 cannot be told apart from the city driving seat of your pants estimate. The same cannot be said for the 5.3/4.8 vs. the 4.3 six cylinder.

I own 4 GMC trucks for work and two are 4.3's, one is a Duramax, and the other is a 5.3. They ALL get 13-14 MPG around town pulling a 2K 5X8 trailer with no highway traveling. This is calculated by hand, not using the trip computer.

I have a 2005 k1500 with the 4.8 I get around 17 mpg. but I live in the country. Its great without a load and not bad with say 1500.lbs. in the bed.

I would'nt use it to tow a boat that size often though.

according to fuel consumption books, 4,8 is 1mpg better in gas compared to the 5.3.

You have 15 hp more in the 5.3 and some more torque. If not towing much, either engine would do the job. My 5.3 I had was cheaper on gas than the 4.8 when pulling my 26 ccraft stinger that was around 8000-8500 pounds.

Check that truck out carefully I don't think Chevrolet combined the Z71 with the 4.8 engine. More than one person has purchased a set of decals from the parts department and made their own Z71 truck. Does the truck have the factory towing package and the G80 locker (positraction) rear? Most 4.8's were base equipment price leaders. There are one pile of great used truck deals out there.

The Z71 option was available with a 4.8. Get me the vin and I can give you all the specs and warranty history. We will see what it is then.

This is the Vin: 1gcek19v43e255925.

For the most part, i will only be towing with this truck a little bit around town and to the launch here and there. Other than that just normal transportation. From what i hear is that under normal driving conditions, the 4.8L is not very noticible over the 5.3L which is what i wanted to hear. As long as is i can use it to tow 7K lbs 5-10 miles at a time that is good for me. Anything longer than that i will use my 3/4 ton diesel. Thanks for the responses guys. MIKE

it has 3.73 gears, Z71, 6400LB GVWR, big charging system. i dont see a towing package, no engine oil cooler, does have skid plates, all recalls have been performed, no warranty work has been done other than recalls. It was originally sold at Grass Lake Chev. in MI. I can fax all this to you if you want.

I had a 2001 chevy extended cab 4.8 liter. It towed my checkmate 251 convincor fine. However, for everyday driving and fuel economy. The 5.3 2003 chevy truck that I had, got better gas mileage then the 4.8 on average. The motor had to work less. Also, talk to any dealer, the resale on the 4.8 is ruff. People don't want it. So if you ever want to trade it back in, you may not be able to get what you think it is worth. Just my .02 cents. So many chevy's for sale, setup with 5.3 I think you should shop around. Lot of trucks for sale with the gas crunch now.

The key statement was that you don't trailer very often. Either motor will get the boat to the water and out. If you're trailering very often buy the biggest motor you can. If it's just an occasional trip, buy the best maintained, cleanest v8 truck you can find.
I've been a GMC dealer for a long time and I see people over buy power all of the time(some do underbuy as well).
The 4.8 is a good motor that is perfect for every day driving. It'll work a bit more in tow but you'll get there. Don't expect much better fuel economy though. There's very little difference in mpgs between any of the gas engines under normal driving conditions.
I don't know what year this truck is but GM has gone back to drum brake rears on 1/2 tons without the Vortec Max package. I'd be more concerned about stopping the boat than pulling it.