Opinions: 8.1 Chevy

Snoboner · Mar 30, 2009

Looking at an 03 Chevy Dually with 8.1 gasser, 2 wheel drive. Want to know how it would pull and handle an 11'6" Camper and tow my 4 place or Jeep in the summer. I have an 02 F-350 7.3 but I'm not secure with the tranny holding up for this application. Just replaced the tranny 2 months ago and my confidence is low. The Chevy has 60,000 miles on her. Thanks

kennyblatz · Mar 30, 2009

personal i would be hanging onto the ford (cant belivie i just said that) the chevy would be fine but i would think mpg would be cut in half, the 7.3 is a good motor if it's been running alright for ya. I am biased for diesels and have no experience with both of those vehicles.

Megadeth · Mar 30, 2009

my dad had an 03 with the 8.1. reliable, towed ok, terrible gas mileage. IMO I'd just stay with what you already have.

ADRENALINE · Mar 30, 2009

Gas sucking pig...other than that nice truck.

AKSNOWRIDER · Mar 30, 2009

I had an 03 suburban with the 8.1..loved it..will outpull any bone stock truck,,..period...fuel economy if you drive it respectably is as good as a 6.0 small block...if you are into going 90 loaded it will get 7 mpg..if you drive it right I could consistently pull 13-14 pulling my steel 4 place loaded..empty it averaged 15-16 driving it easy...it will outpull your 7.3 easily...

NapaMatt · Mar 30, 2009

8.1 Gas MPG

ya.. If you want to Start paying more in Fuel... Its ok.. 9.3 Unloaded.. 8.1 to 7.8 Loaded!!!! Be sure to put any extra Tranny cooler.... atleast Watch the temps!!! Nice Truck... I am a Chevy man though... lol..

theultrarider · Mar 30, 2009

I've got a 7.3 ford (96) and my Dad has an 8.1 gasser. His 8.1 will pull corcles around my 7.3, not even close. That motor is a monster. Dad bought this truck new and uses it to tow a triple rig...25ft 5th wheel trailer with slides, and behind that, an 18ft Hewescraft with a 150hp and 15hr hanging of the back of it. He goes all over the lower 48 and canada with this rig. He has about 150,000 miles on it now with ZERO issues. He having pulled just the boat with a cabover camper up here to Alaska several times as well. The empty milage will not match the deisels, but is still not too bad 13-14. Loaded with both trailers cruise set at 70 he gets about 8-9 mpg. Te deisels are not going to get much more. My 7.3 has been a good reliable truck for me, but this will be my last one. Next truck will be either a 6.0 chev or 8.1. There are too many inconviences with the deisel for me. Cold starts with no where to plug in, Nothing worse than coming back from the cabin after a weekend of riding to find out the truck won't start at -20 or -30 in the middle of no where with no way of plugging it in or warming it up. The expensive oil changes, trying to fuel the truck and the toys without makeing circles around the gas station from pump to pump. There are many more. And now in Alaska anyway, deisel is still holding at a dollar gallon higher than gas. It just does not add up for me anymore. If you are going to use the truck primarily tow tow large loads, I think you will love the 8.1...used as a grocery getter, you are looking at 13 mpg....

Megadeth · Mar 30, 2009

AKSNOWRIDER said:
I had an 03 suburban with the 8.1..loved it..will outpull any bone stock truck,,..period...fuel economy if you drive it respectably is as good as a 6.0 small block...if you are into going 90 loaded it will get 7 mpg..if you drive it right I could consistently pull 13-14 pulling my steel 4 place loaded..empty it averaged 15-16 driving it easy...it will outpull your 7.3 easily...

uhh.. I disagree. It might outpull any bone stock gas powered truck.

AKSNOWRIDER · Mar 30, 2009

Megadeth said:
uhh.. I disagree. It might outpull any bone stock gas powered truck.

when mine was new..it out pulled new d-max...new ford diesel and a cummins..all 03's..maybe I got a good one..but we have 5- 8.1's at work as well as 4 d-maxs(all in 2.5 ton trucks)..8.1's will out pull the d-maxs loaded thru the hills every time....these trucks range from 01's to 08's...in the big trucks loaded the d-maxes average 2 mpg better..empty they do about 6 mpg better...the 2 newest d-maxs 08's are always having problems with the exhaust emissions as well...

theultrarider · Mar 30, 2009

Megadeth said:
uhh.. I disagree. It might outpull any bone stock gas powered truck.

I'm with aksnowrider on this. Like I said, Dads 8.1 runs past my 7.3 when we both have cabover campers on and with boats behind us pulling a long steep grade. I'm down to 50mph and steady there for a mile to the top, Dad back out of it when he hit 100mph. They are impressive.

Beels · Mar 31, 2009

I have an '01 GMC 2500HD c-cab, s-box, 4X4 with the 8.1. Love it. The Allison behind the big block is flat out awesome. Gets the same gas mileage empty as my old man's '00 6.0L gasser. Handles everything I need to tow with it, just fine. Pulled Hobbes' 25' enclosed from Bismarck, ND to Afton, WY, set the cruise at 80 mph on the interstate and it stayed there. Got around 6mpg at that speed. Sure, diesels will get slightly better mileage, but it doesn't pencil out for me. Don't listen to these clowns that will claim mid to high teens for mileage with diesels pulling encloseds at that speed. I haven't seen one yet that will do it.

jthussey · Mar 31, 2009

If your looking for a gasser. The 8.1 is probably your best bet. And i'm a ford guy. You wont have the maintenance costs as a diesel (oil changes). It will not tow better than a diesel though. The 7.3 is a great motor. Its a decission you will have to make. Both are good pulling engines but theres no way a 8.1 will touch a diesel for pulling and thats a fact. Have a good one.

GlennRMK · Mar 31, 2009

8.1 is great engine IMO.

Best pulling gas engine out there by far.

I would expect 13-14 empty and 7-9 loaded.

If you have an 02 7.3, do yourself a favor and keep that and do some tranny work. A nice aftermarket converter and valvebody will make a big difference.

Then get a programmer if you don't already have one. Know a few people that like the Diablo.

And make sure you have gauges (tranny temp, pyro and boost).

Snoboner · Mar 31, 2009

I'm keeping the Powerstroke for sure. I have gauges, Bullydog 6 bank, 4" exhaust, AFE intake etc. etc. Just dumped 3 grand into a new tranny at 120,000 miles and don't trust it for the heavy stuff anymore. Want something that I can leave the Camper on and tow with and use my stroker for every day use and towing. Just can't justify spending the extra dough in these times for another diesel rig. You can buy a lot of gas for the difference in maintenance and initial costs.

CATillak · Mar 31, 2009

As much as i dislike GM trucls and even the 8.1 for the leaky bastard that it is, it will pull a trailer to like no other. maybe not modded diesels, but it does pull fast and hard, that being said, keep the 7.3

Beels · Mar 31, 2009

CATillak said:
As much as i dislike GM trucls and even the 8.1 for the leaky bastard that it is, it will pull a trailer to like no other. maybe not modded diesels, but it does pull fast and hard, that being said, keep the 7.3

What leaks? Mine has 165,000 miles on it and it doesn't leak. Have a slight leak on the Allison, but that's it.

Iowaplowboy · Mar 31, 2009

The 8.1 will pull whatever you can hook it up to. Just keep an eye on the oil. I had one that used oil, the hired man ran it out of oil at 80,000 miles and ruined the engine. When I was looking for a used engine to stick back in it, I found out that they do have an oil consumption problem - no big deal if you just keep an eye on it.

I think the 8.1 with 3:73 gears and the Allison tranny will get about the same mpg as the 6.0 with 4:10. When you go to pull, the 8.1 will do its job.

CATillak · Mar 31, 2009

Beels said:
What leaks? Mine has 165,000 miles on it and it doesn't leak. Have a slight leak on the Allison, but that's it.

92000 on ours, and yes it burns an excessive amount of oil, but it leaks out of the main seal and oil cooler lines and the tranny doesnt leak but it does slip in 2nd gear. Now, maybe you got a better truck? As ours has gone through 2 fuel pumps, nothing electrical works right, And its spent majority of it time with the check engine light on and not being able to pass IM. This goes along with the other experiences weve had with GM trucks, all the same problems, and they all started around 80000miles. I know ALL trucks have their leaks and especially oil cooler lines, but it started soo early and is so bad that its jsut turned me off of the motor. I would like to stick one in a car and make a monster, but ill stick with my diesel for towing.

One last opinion, i think the majority of the 8.1s somewhat decent highway mileage is due too the allison, it runs at a very low rpm at higher speeds.

PS the guy in your avatar is hilarious

Beels · Mar 31, 2009

CATillak said:
92000 on ours, and yes it burns an excessive amount of oil, but it leaks out of the main seal and oil cooler lines and the tranny doesnt leak but it does slip in 2nd gear. Now, maybe you got a better truck? As ours has gone through 2 fuel pumps, nothing electrical works right, And its spent majority of it time with the check engine light on and not being able to pass IM. This goes along with the other experiences weve had with GM trucks, all the same problems, and they all started around 80000miles. I know ALL trucks have their leaks and especially oil cooler lines, but it started soo early and is so bad that its jsut turned me off of the motor. I would like to stick one in a car and make a monster, but ill stick with my diesel for towing.

One last opinion, i think the majority of the 8.1s somewhat decent highway mileage is due too the allison, it runs at a very low rpm at higher speeds.

PS the guy in your avatar is hilarious

Sounds like you've had some bad luck.

Since I changed my cooler lines, my oil consumption has dropped to a quart and a half per oil change, on average. I should also add that I quit using full synthetic oil and it helped as well. Go figure on that one... I was using Castrol Syntec 5W30 in it since I bought it (used). Switched to 76 Brand synthetic blend 5W30 and it slowed the consumption down some more. at least a half quart per change.

06MXZXRenegade800 · Mar 31, 2009

Im not much of a ford fan, but truthfully, you have the 'cream of the crop' as far as the 7.3 flowerpokes go.

As with any of the big gassers, they will pull pretty much anything you hook up to it but dont even worry about gas milage, just make sure their are lots of gas stations on the way and lots of $$ in the bank account!

I would keep the ford, its at least going to have decent fuel economy loaded and unloaded. If the transmission becomes an issue in the future most 'flaws' can be worked out with aftermarket parts or transmission (which is what you should have done the first time!)

Opinions: 8.1 Chevy

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