6.0 or 8.1

Stepside Z · January 11, 2002

If you had to choose between two identical trucks. 2500HD Reg Cab 4X4. One with a 6.0, auto, 4.10, the other with a 8.1, auto, 3.73 which would you choose? What would the mpg difference be during normal day to day driving?

Shaners · January 11, 2002

John,

Mileage wise, I don't think it would be more than 1-1.5 mpg's.

I love the 6.0L in my truck!!! Yes the 8.1L would be awesome, but I have no use for it as a daily driver. I tow a heavy load about 200-300 miles a year, and the 6.0L does fine. If I were to tow more often, I would have gotten the 8.1L, but I couldn't justify the minimal loss of mpg's and the cost of the Ally tranny!!!

BTW, 1-2 mpg's in these trucks (which aren't thrifty) is only 2-3 tankfulls a year difference...

kengsxr · January 11, 2002

my 2000 6.0 got 14 hwy my 2001 8.1HD gets 11.5 hwy

Kansas Kid · January 11, 2002

Since you want to compare each of them being mated to an auto transmission, I would go with the 6.0 anyday of the week. I do not like the cost of the Allison auto nor am I particularly fond of its operating characteristics and amount of power it sucks up. But if you were considering a manual tranny I would get the 8.1. Heck for the measly cost of the 8.1/ZF upgrade, it might come out cheaper then a truck with the 6.0/4L80E

Jpshostr · January 11, 2002

Stepside, if this truck would be for you I'd go with the 6.0L. 300 horse is plenty for a guy that is daily driving and rarely towing, plus its cheaper as you aren't paying for that bigger engine or Allison tranny. But I do gotta say one thing, 3.73 gears make me cringe. Go 4.10s behind whatever motor you'd get.

VegasDude · January 11, 2002

I bought the 8.1 and I love this engine. I am getting 12.5 on the road and 10.5 in town and 10 towing a 4000 pound trailer and quads........

DigUout · January 11, 2002

If I couldn't tow it (whatever "it" is) with a 6.0 and 4:10's, I'd just get a manual DMax with 4:10's.

I don't understand the thinking of, "I need the big block for more power, but I only need 3:73's." What?!?!?

CMNTMXR81 · January 11, 2002

Well obviously the 8.1! Why would you spend all that cash to get the 8.1 and the Allison and then only go 3.73's? Go 4.10's!

I have that, 8.1, Allison and 4.10's. I wouldn't have it any other way. I can't really comment on fuel economy cause A) I don't really monitor it and B) I don't care! I didn't buy this truck because of it's fuel economy. I bought it for power and towing prowess.

Beaux Duke · January 11, 2002

I went with the 8.1, Allison and 3.73. Funny thing about the 4.10 with the 8.1 - the tow rating was the same: 12,000 lbs. At least that's what my owners manual says.

I have absolutely NO problems pulling my 6500 lb travel trailer. My 99 Yukon wasn't up to the task but the HD is!

Mileage is not great 10.2 towing. Highway (not towing) best so far (1200 miles on odometer) is 11.95 at 70 with cruise on. Probably would be better if I would accelerate more slowly from stop lights!

I drove the 6.0 and it was nice and would have done the job for me but the 8.1 gives me room to move up in size with my travel trailer.

Put it this way... you can never have too much truck!

A buddy at work bought the Duramax. He rides me hard about the mileage difference. I ride him about the noise and smell. Both are very nice vehicles.

If gas goes too high, my backup plan is to take the money I saved by not buying the diesel and purchasing a Nissan Frontier from my paw-in-law to commute with.

kc2aku · January 11, 2002

i have a 6.0 in a reg cab long box and it is perfect. i get 13mpg empty, load, or trailering.

antig24 · January 11, 2002

i would get the 6.0 if it is just ur daily driver and u aren't going to tow anything

Stepside Z · January 11, 2002

Thanks for the input guys. I am thinking about a new truck the end of this year and it seems like we have so many choices.

Kansas Kid · January 12, 2002

If I couldn't tow it (whatever "it" is) with a 6.0 and 4:10's, I'd just get a manual DMax with 4:10's.

Naw you wouldn't do that. Mainly because you can't get 4.10's with the Duramax. Atleast not for a few more years anyways, until GM wants to up the GCWR of the HD trucks a few thousand pounds, then they might offer some 4.10's with the Duramax.

Honestly though, I think the Dmax is the only GM motor I would have to seriously consider not wanting 4.10 gears. Rpm kill fuel mileage on diesels, and its already running some pretty high rpm with the 3.73 gears and stock tires. Might be worth it when running large tires, or pulling over 15,000lbs. This one would be a tough decision for me.

Jason@RDowningChevy · January 12, 2002

I would prefer the 6.0L to the 8.1...Then again I don't need to tow 12,000 LBs!!!! :0

mhsneon · January 12, 2002

4.10's with the 8.1 and the 6spd is the way to go. I also was not concerned about gas milage when I bought it. I can't complain I get any where from 8-10 in town and 10-12 on the highway at 85. Towing 5000lbs I get about 11mpg. The 4.10's are worth it if you are going to tow.

2001 Sierra 2500HD RegCab 8ft bed 4x4 8.1 6spd 4.10's