• Don't miss out on all the fun! Register on our forums to post and have added features! Membership levels include a FREE membership tier.

GM 6.6 gas

FatDogX

Well-known member
Lifetime Membership
Dec 27, 2008
3,307
1,578
113
ND
I have a buddy that has one but he just got it and no reports back yet??

On a side note my father-in-law has been running the Ford 7.3 gas and good reports back on that.
 
S
Nov 26, 2007
1,403
971
113
utah
while we're waiting for reviews.....i've used mostly diesels from Ford and Dodge for last 35 years or so but got a 6.2 six speed F-250 three years ago; smooth, quiet engine that had zero problems; had to run 3-4k rpm pulling 12k lbs in Utah mountains; gas mileage was about 1.5 to 2.5 less than '16 F-250 diesel, but fuel prices are generally 25-50 cents per gallon cheaper, no def, and all other maintenance was notably less....got a 7.3 gas F-250 about a month ago; it gets better mileage than the 6.2 (less rpm always), not quite as smooth as the 6.2 above 3k rpm, but still nice; pulls way harder, but won't pull hills as hard as a diesel, but much stronger than the 6.2, and the 10 speed always has a gear that's just right; pulled some steep hills to my local lake, 6.2 would pull them about 40 mph, the 7.3 about 50-55....won't know about long trip mileage until next month when i do 400 miles to Lake Powell, but i'm estimating about 10 mpg with the 7.3, the 6.2 would get 9.3-9.5, and my diesels 10.8-11.0, same load...nice thing about the diesels, you could set cruise at 65 mph, and forget it...generally pulled about 5 mph less with the gas engine, just so i wouldn't work it so hard during summer heat, also anything above 65 and even good quality trailer tires would start blowing above about 90-95 degrees....for what it's worth
 

FatDogX

Well-known member
Lifetime Membership
Dec 27, 2008
3,307
1,578
113
ND
while we're waiting for reviews.....i've used mostly diesels from Ford and Dodge for last 35 years or so but got a 6.2 six speed F-250 three years ago; smooth, quiet engine that had zero problems; had to run 3-4k rpm pulling 12k lbs in Utah mountains; gas mileage was about 1.5 to 2.5 less than '16 F-250 diesel, but fuel prices are generally 25-50 cents per gallon cheaper, no def, and all other maintenance was notably less....got a 7.3 gas F-250 about a month ago; it gets better mileage than the 6.2 (less rpm always), not quite as smooth as the 6.2 above 3k rpm, but still nice; pulls way harder, but won't pull hills as hard as a diesel, but much stronger than the 6.2, and the 10 speed always has a gear that's just right; pulled some steep hills to my local lake, 6.2 would pull them about 40 mph, the 7.3 about 50-55....won't know about long trip mileage until next month when i do 400 miles to Lake Powell, but i'm estimating about 10 mpg with the 7.3, the 6.2 would get 9.3-9.5, and my diesels 10.8-11.0, same load...nice thing about the diesels, you could set cruise at 65 mph, and forget it...generally pulled about 5 mph less with the gas engine, just so i wouldn't work it so hard during summer heat, also anything above 65 and even good quality trailer tires would start blowing above about 90-95 degrees....for what it's worth

Definitely keep us posted on your 7.3!!!
 

goridedoo

Well-known member
Premium Member
Feb 8, 2010
3,868
3,544
113
I have no experience... but have been doing a little "shopping" for a new gasser, thinking I'm due. Love my Duramax... but gassers are just simpler, in like every way, and cheaper so I might go that route.

Sounds like the 6.6 gasser is a bit of a dog. Reviews on the entire truck are pretty poor from what I've seen. Many seem to think a better transmission would really help. 10 speed Allison?

The Ford 7.3 sounds like a great motor/tranny combo so far. I'll probably wait another year or so to see some more reviews. Ram and Ford will likely both have major updates to their heavy duty trucks by 2022 as well.
 

Hawkster

Well-known member
Lifetime Membership
Apr 22, 2010
8,122
6,384
113
AK
I'm also shopping , The first question I have is why did they not put an Allison 10 speed in the 6.6 gas ??? Really ??? Did not the 8.1 have an optional Allison ??? Am I missing something .
Thanks for not making a better sale . I'm looking for a 17 or 18 HD , I'll Whipple it .
Put a 10 speed in the 6.6 and can you imagine how many coal burners would switch over ?
The work truck version is a joke , steering wheel is plastic for starters , I got out faster than I got in .
 
S
Nov 26, 2007
1,403
971
113
utah
so i did the Lake Powell trip, 800 miles round trip, lots of hills, fairly steep and long with elevation gains of 1500 feet or so on one pull...the truck is '20 f-250 with the 7.3 gas, 10-speed, and 4.30 diff.....i added air bags to take care of the rear end sag, which wasn't too bad anyway...the load is boat that weighs 12k, is 9.5 wide and 11.5 high which is a pretty good air resistance also.....compared to a 17 power stroke and 17 6.2 gasser, this is what i found for gas milage for the exact same trip and same load....same speeds, near same temperatures and other conditions....powerstroke 10.8 average plus def cost; 6.2 got 9.3 average on premium; 7.3 got 9.8 on premium.....aside from the fuel milage, the new f-250 is my best overall truck to date, i get new one every 1-3 years depending on need and my bank account, smooth riding empty (i use 62 psi when empty, 76 when pulling heavy)....the truck has some serious grunt when pulling hills, topping any off them at legal speed limit, rpm runs about 1000-1200 less than 6.2 gasser, and about the same as my last diesel....with the 10 speed, i always have a gear that's just right...never overheats, trans temp stays reasonable at 190 to 215, maybe up to 230 or so on long hills with my foot in it and outside temps 80-90 degrees...i find all other aspects to the truck to be easy to use and well laid out....no real complaints....time will tell on durability, but i've had good luck with ford trucks in general....
 

Ox

Snowest's Axe Murderer
Lifetime Membership
Premium Member
Jul 8, 2001
1,523
603
113
NW Ohio
www.midwestproductionmachining.com
so i did the Lake Powell trip, 800 miles round trip, lots of hills, fairly steep and long with elevation gains of 1500 feet or so on one pull...the truck is '20 f-250 with the 7.3 gas, 10-speed, and 4.30 diff.....i added air bags to take care of the rear end sag, which wasn't too bad anyway...the load is boat that weighs 12k, is 9.5 wide and 11.5 high which is a pretty good air resistance also.....compared to a 17 power stroke and 17 6.2 gasser, this is what i found for gas milage for the exact same trip and same load....same speeds, near same temperatures and other conditions....powerstroke 10.8 average plus def cost; 6.2 got 9.3 average on premium; 7.3 got 9.8 on premium.....aside from the fuel milage, the new f-250 is my best overall truck to date, i get new one every 1-3 years depending on need and my bank account, smooth riding empty (i use 62 psi when empty, 76 when pulling heavy)....the truck has some serious grunt when pulling hills, topping any off them at legal speed limit, rpm runs about 1000-1200 less than 6.2 gasser, and about the same as my last diesel....with the 10 speed, i always have a gear that's just right...never overheats, trans temp stays reasonable at 190 to 215, maybe up to 230 or so on long hills with my foot in it and outside temps 80-90 degrees...i find all other aspects to the truck to be easy to use and well laid out....no real complaints....time will tell on durability, but i've had good luck with ford trucks in general....
Could you give us a run-down on the empty milages too?

Sounds very interesting.

5 years ago I had to Schidt or git off the pot ... well, no - I really did need to Schidt...

I was likely NOT going to get a new diesel. At that time tho - about the only gassers available for bigger trucks was a bigger Hemi, and that's about it I think?
I have a 1 ton flat bed that usually just hauls it's loads, but doo occassionally hook on to a big goose, but not enough to make that my main concern, but the headache rack on the flatbed pulls the oil burners down 2mpg from stock bed.

I ended up fetchin' a 10 yr old truck from Florida with a Cummins, and I'm likely a long way out from this one rusting out yet, but hearing that there is some bigger gassers coming on the market - with comparable milages is nice to hear!
 
S
Nov 26, 2007
1,403
971
113
utah
just completed 1100 mile road trip....mostly 70 mph freeway, some 65 two lane, some 40-45 in yellowstone park....16.3 for trip, wife and i, few tools and cooler....i've gotten as high as 17.2 and as low as 14.8 for empty truck....generally mountain driving, 14.8 was hilly freeway at 75....
 
Premium Features