4.8 or 5.3

Stepside Z · April 26, 2001

I have been looking at new trucks for quite some time now. I considered a new Duramax but when all factors are considered I have decided against it. My current truck has a 4.8 and seems to have good power and fuel economy. I tried a new reg cab stepside today with 4.8/auto/3.73 and all desired options. My question is would you go with the 4.8 or order a new 5.3? Also I am interested in what kind of MPG you 5.3 guys are getting.

(Edited by Stepside Z at 10:23 pm on April 25, 2001)

April 26, 2001

There is no substitute for cubic inches (or liters in this case).

The 5.3 has a longer stroke, therefore should have more torque.

Shaners · April 26, 2001

The 5.3L litre has more torque and more HP and can tow about 1000 lbs. more than the 4.8 litre if both are equipped with Automatics. Hp and torque for the 4.8 is 270 hp and 285ft llbs respectively. The 5.3 is 285 hp and 325 ft lbs respectively.

I'm going to venture a guess and say the 4.8L will get slightly better mpg's. I drive my 5.3L in town at least 80% of the time and go on short trips (it's a small town and I usually put less than 10 miles per day on it). I average around 14 mpg's with the truck in my signature, and it has the 3.73 rear gears.

April 26, 2001

How does the 6.0 and 8.1 add to those numbers?

Shaners · April 27, 2001

The "old" 6.0L was rated at 300hp and 360 ft lbs of torque. I believe that motor is now at 325 hp and I'll guess torque is up at least a little.

The 8.1L is 340 hp and 455 ft lbs of torque!!!

And the 6.6L diesel is 300 hp and 520 ft lbs. of torqe!!!

What a line up of stump pulling power!!!

summitXMK · April 27, 2001

What year do you have to get to get the NEW 6.0?

Shaners · April 27, 2001

I think the new 6.0's are available now in trucks like the 1500HD. There is even a higher output version in the Escalade (Caddy) and GMC C3. Somewhere in the neighborhood of 340-345 hp.

I'll have to check, but the newer 325 hp is more than likely the stock motor in the 2500HD's also.

OK, I checked it out...

The stock motor in the 2500HD is the newer 6.0L rated at 325 hp and 355 ft lbs of torque. This would be the current 2001 model, I'm assuming the switch to the newer 6.0L took place at the beginning of that production year, but I have no way of really knowing that for sure.

April 28, 2001

So here's what we've got on the current GM motors:

hp torque(lb.ft.)

4.8 270 285

5.3 285 325

6.0(old) 300 360

6.0(new) 325 355

8.1 340 455

6.6(dsl) 300 520

I hope this is right. If so, it is impressive.

Stepside Z · April 29, 2001

I may go with the reg cab, stepside, Z71, 4.8. I don't tow or haul anything so I feel the truck will work out fine for me. I will keep you all posted.

HiG4s · May 10, 2001

The big difference is you can get a 4.8 with a M-5 and the 5.3 has to have an auto.

The only mechanical difference from the 4.8 to the 5.3 is the crank. Change the crank on your 4.8 and you have a 5.3.

The only difference between the 5.3 and the 6.0 is the bore. Bore your 5.3 and you have a 6.0.

May 10, 2001

Quote: from HiG4s on 8:18 pm on May 9, 2001
The big difference is you can get a 4.8 with a M-5 and the 5.3 has to have an auto.

The only mechanical difference from the 4.8 to the 5.3 is the crank. Change the crank on your 4.8 and you have a 5.3.

The only difference between the 5.3 and the 6.0 is the bore. Bore your 5.3 and you have a 6.0.

Okay, new GM experts. I need to go to school here. It has been my understanding that the 4.8, 5.3, and 6.0 are all small block V-8 engines with the new Vortec head design. The displacements were altered to make the most efficient bore/stroke designs. I was told over at PUTC that it is a totally new block design as well.

Who's right?

HiG4s · May 10, 2001

Well yes and no, it is basically a gm small block, but it is actually a cast iron version of the Z28/Trans Am/ Vette LS1 engine block which IS a different casting and will not interchange all parts with previous LT1 castings.

If you go back through the years many times there have been "completely new" blocks which a few years later were considered a variation of the basic GM small block. So I guess it is a matter of perspective.

Shaners · May 11, 2001

You hit the nail on the head HiG4s. At least that is the way I understand it too...

tstranik · May 14, 2001

>So here's what we've got on the current GM motors:

> hp torque(lb.ft.)

>4.8 270 285

>5.3 285 325

>6.0(old) 300 360

>6.0(new) 325 355

>8.1 340 455

>6.6(dsl) 300 520

I'm pretty sure the 6.0 has 370 Ft*Lbs of Torque.

vhato · October 1, 2001

TO add more to the mess of comparos, The 6.0l engine has iron heads and a few other minor differences in valve actuation. On paper it only has a larger bore over the 5.3