Engine Comparison

Chuggernaut · June 13, 2001

Does anyone know of a website that compares the horsepower, torque and perhaps mpg ratings of the new ('99-up) Vortec's versus the older models? I know I've seen a table somewhere, but I can't remember where.

My reason for asking is that we're looking at replacing our company '98 Suburban 2500 with the 454 with a newer generation model. In particular, I wanted to see how much better the 6.0 and 8.1 are.

Thanks.

Pastmaster · June 13, 2001

The Gm site gives graphs. They won't show mpg's for hd trucks though. www.gmpowertrain.com

I think the 7.4L is still produced in the Big Van's, but it might have been replaced with the 8.1L. A brochure might be of help too.

The 6.0L will get the best mpg, and the 7.4L and new 8.1L's would get darn close from what I've heard.

(Edited by Pastmaster at 5:02 pm on June 13, 2001)

BIG BLUE · June 16, 2001

Chuggernaut,

If your going to replace the current 2500 Sub with a new 3/4 ton Sub then I would get the 8.1L. I think you'd be disappointed in the response of the 6.0L in a 3/4 ton truck, especially since your used to having the 454.

The mileage will not be that different but the gain in horsepower/torque will be worth it IMHO. Sorry, can't provide the graphs. I like the smile indicater myself; that's when you drive one truck with a small block, then test drive one with the big block and see how much bigger your smile gets

Good Luck,

BIG BLUE

Chuggernaut · June 16, 2001

Thanks for the insight, guys.

Seeing that it'll be used like this one is, including towing the trailers for the VP's dock to his river lot, I'm hoping for the 8.1L. I'm already certain that he'll have his say in that it'll be an LT with the leather. WOO-HOO!!

If it were up to me, the "smile indicator" would be a HUGE factor, especially considering that the $$$ is coming out of the corporate pocket!!! :biggrin: :biggrin: :biggrin: :biggrin:

I'll keep ya posted.

(Edited by Chuggernaut at 2:01 am on June 16, 2001)

(Edited by Chuggernaut at 2:02 am on June 16, 2001)

Jpshostr · June 17, 2001

I think the 6.0L is more comparable to the old 350, and the 8.1L to the 454.

How about you just push the diesel on them?

Kansas Kid · June 17, 2001

A couple things to think about on this issue.

If the Suburban is going to be used, finding one with the 8.1 is going to be very difficult. The 2001MY was the first they started putting the 8.1 in the new style Burb, and not many at all came with it.
Keep in mind that the 8.1 was designed with having an Allison auto or the ZF 6-speed behind it. In the Surburban it will come with the 4L80e, which although it is a good transmission, is on the edge of its operating range behind this motor. I've read posts from GM engineers that if left on its own, the 8.1 will tear the 4L80e to shreads. Needless to say, the 8.1 is going to have its fuel delievery severly hampered when in 1st gear, so it probably won't be much different then the 7.4 you are used to driving.
And third, there is no diesel option for the Suburban as of yet, and when the Duramax is offered, it will be detuned to allow the 4L80e to survive for any reasonable amount of time.

Just some of my thoughts...

Jpshostr · June 18, 2001

Quote: from Kansas Kid on 8:41 pm on June 17, 2001
A couple things to think about on this issue.

If the Suburban is going to be used, finding one with the 8.1 is going to be very difficult. The 2001MY was the first they started putting the 8.1 in the new style Burb, and not many at all came with it.

Keep in mind that the 8.1 was designed with having an Allison auto or the ZF 6-speed behind it. In the Surburban it will come with the 4L80e, which although it is a good transmission, is on the edge of its operating range behind this motor. I've read posts from GM engineers that if left on its own, the 8.1 will tear the 4L80e to shreads. Needless to say, the 8.1 is going to have its fuel delievery severly hampered when in 1st gear, so it probably won't be much different then the 7.4 you are used to driving.

And third, there is no diesel option for the Suburban as of yet, and when the Duramax is offered, it will be detuned to allow the 4L80e to survive for any reasonable amount of time.

Just some of my thoughts...

After I typed my above response I just remembered that their is no diesel available as of right now for the 'burban, wish there was though. Guess I was just too lazy to edit.

Pastmaster · June 18, 2001

The 2001MY was the first they started putting the 8.1 in the new style Burb, and not many at all came with it.

I've never seen one. Have you?

Kansas Kid · June 18, 2001

Quote: from Pastmaster I've never seen one. Have you?

No, I haven't. I haven't been looking that much, but I haven't even seen that many 2500 Suburbans in general.

Chuggernaut · June 18, 2001

It's a pain in the butt trying to find a crew cab 2500HD around here, but for some reason, the 2500 'Burbans are rather plentiful. But you're right, the 8.1's are rare -- I've only seen two.

But knowing my bosses, if they know it's available, there's a good chance they'll order one.

Now that I'm thinking about the engine thing though, I thought the 5.3 was comparable to the 350 and the 6.0 was along the lines of the 454 from a power standpoint, leaving the 8.1 to be a whole new powerhouse. Or am I wrong in saying this??

Jpshostr · June 18, 2001

Quote: from Chuggernaut on 1:36 am on June 18, 2001
Now that I'm thinking about the engine thing though, I thought the 5.3 was comparable to the 350 and the 6.0 was along the lines of the 454 from a power standpoint, leaving the 8.1 to be a whole new powerhouse. Or am I wrong in saying this??

Based on the applications that I've been seeing GM put the engines in, I think that the 6.0L is taking the place of the 350 and the 8.1L of the 454. Trucks that used to come with the 454 get the 8.1L, ones that used to get the 350 get the 6.0L. The 5.3L is more based on the person that wants a truck but doesn't intend on using it as a truck in my opinion.

Shaners · June 18, 2001

horsepower for the 5.3L is 285 and the 6.0L is 300 on older ones and 325 on newer ones.

There are 5-6 crewcabs on lots around here... they just aren't selling I guess!!! I saw a 2500HD with the crewcab duramax and 6 speed saturday. It stickered a little over ?k

Pastmaster · June 18, 2001

I see quite a few 2500 suburbans. More than I saw of our style (1992-1999). In suburban language, the 5.3L replaced the 5.7L, the 6.0L replaced the 5.7LHD, and the 8.1L replaced the 7.4L.

The 2001 GMC Yukon XL brochure states the 6.0L's hp at 315 and torque at 360ft/lbs of torque. My dealer states this too. I've not heard 320hp in anything except the Denali's.

Shaners · June 18, 2001

I believe the 6.0L in the new Caddy is rated @ 345 hp on premium fuel...

BDBWTE · April 30, 2002

Owning a 454 BB I would go out and get the 496, 8.1 liter. Although the 6.0L is a great motor if your used to the power of a big block you better stay with it because if not I think that you'll be disappointed in the 6.0 because it will not perform the same as the 8.1L..