6.6 GM. Gas

[Busdriver]

Wondering about the 6.6 GM gas engine. Tow weight is about 11,000 lbs. thinking about going with the gas engine next time I buy . Pro’s or con’s also wondering about fuel mileage towing. I know if you have to ask about fuel mileage shouldn’t be towing!

[Dadoffourgirls]

So I had a reg cab dually gasser from Oct 2019 to Dec 2020. I logged 16324 miles. My average economy was 13.0. it was 459 engine hours, 79.6 idle engine hours. I hauled two different gooseneck trailers, 547 miles for one, 761 miles for the other. Avg economy was 8.2 mpg. This trailer was loaded with 14 large round hay bales for half that mileage, empty the other half. Country roads, with some stop signs and traffic lights. I towed my travel trailer, averaging 8 mpg. A friends travel trailer only got 7.3. My average with my aluminum stock trailer was 10.8. I used 4% of my front brake life, 3% of the rear. I have pictures of all this data. I had measured with manual calculations many times, and the computer was very close.

If I was planning to keep my truck on order, I would have thought more about the gas engine. Since I am planning to flip, diesel was my decision.

I used a 2019 crew cab dually diesel to take my trailer to Kansas in July 2019, and averaged 9.9 mpg. I used my Express with the 6.0 gas to take my trailer to Iowa, and averaged 9. (I found an air deflector the day before departing, and driving 62 mph, I achieved the 9 mpg).

Overall, I have been satisfied with my gas engines.

[ksss]

My experience with my GM trucks shows the DIC is inside 1 mpg when compared with doing figuring it manually, and when using the average at 400 miles it is within .5 mpg. To get that kind of mileage on a mix of city/highway mpg is good mpg for HD gas pickup.

[MFL]

Vintage465 wrote:

Sjm9911 wrote:
That works too! Lol.
But I am serious about the millage,14.2 average over the last 400 miles. So, I do half highway and half city. Thats dictated by where I live. If the site was easier to post a pic, i would. The towing was averaged, over the last disney trip. So, 1200? Miles each way. It will also depend on the driver and if you ride the brakes I guess. But its a real figure. As close as I can tell.

So I'm wondering here. I don't use the dashboard computer to get my mileage. I take the miles driven, divided by the fuel used in gallons. How do you guys calculate your actual mileage?

While I think the driver information center (DIC), is a very useful tool, it seems more about averages, when figuring mileage. IMO, your, my method gives more accurate results. Of course, most accurate mpg should be figured over lengthy distance, all in city, all on interstate, or all towing, at normal traveling speed.

Trucks mileage, towing capability, both improved, with the move to 6-speed, eight, and ten speed transmissions. To me though, the biggest noticeable improvement was the 6-speed, with ability to lock out upper gears.

Jerry

[Sjm9911]

Vintage465 wrote:

Sjm9911 wrote:
That works too! Lol.
But I am serious about the millage,14.2 average over the last 400 miles. So, I do half highway and half city. Thats dictated by where I live. If the site was easier to post a pic, i would. The towing was averaged, over the last disney trip. So, 1200? Miles each way. It will also depend on the driver and if you ride the brakes I guess. But its a real figure. As close as I can tell.

So I'm wondering here. I don't use the dashboard computer to get my mileage. I take the miles driven, divided by the fuel used in gallons. How do you guys calculate your actual mileage?

For me, i use the dash, i have a 36 gallon tank. I was at e, but not at the get fule now light, my truck took 36 gallons. So its hard to tell what you used also. Both are just rough gauges in my opinion. I will say, the truck gets about the same as my 2012 sierra, and I think both were better then my 2014 JKU.

[Vintage465]

Sjm9911 wrote:
That works too! Lol.
But I am serious about the millage,14.2 average over the last 400 miles. So, I do half highway and half city. Thats dictated by where I live. If the site was easier to post a pic, i would. The towing was averaged, over the last disney trip. So, 1200? Miles each way. It will also depend on the driver and if you ride the brakes I guess. But its a real figure. As close as I can tell.

So I'm wondering here. I don't use the dashboard computer to get my mileage. I take the miles driven, divided by the fuel used in gallons. How do you guys calculate your actual mileage?

[ksss]

That is pretty impressive.

[MFL]

Mileage looks good! The DIC is not always perfect but close!

If you copy paste this on your search line, should take you to forum pic drop or drag pic, or select. http://photoposting.is-great.net/?i=1

I was towing my 7x23 aluminum v-nose sled trailer across a remote area, cruise set at 70 BSn with buddy, noticed the side/head wind picking up, looked at display showing 6.9 mpg!!! I knew my next fuel stop about 70 miles ahead. I brought up miles to empty 37...not good!!

I have a 35 gal tank, should have been no problem. I slowed to 50 mph, cruise off, slower up hill, coasted down hills. What happens when miles to empty reads 0?? Nothing, but continued on at 50 mph. Made it, put in just over 35 gal. Yup, display lied, went 35 miles, after tank showed empty!

Anyway, you learned to post pics, and a seem a cool dude! 🙂

Jerry

[Sjm9911]

Ok, used a diffeent link. And that worked.

[Sjm9911]

[Sjm9911]

Still getting "The following problems were encountered while processing your request:

> Your message contains invalid formatting. Please use the toolbar provided to ensure proper formatting.

Then i used every icon on the toolbar, and nothing but the same response.

[Sjm9911]

See if that worked. The 15 best, i have no idea what that means. Might be for a set period? Not sure. I do know i clocked the miles in the smaller range and I got around 12 around town. So with that , and the roughly 50/ 50 highway and city , it should be about 16 highway and 12 city. Or I'm getting better then 12 city and a little less on the highway. But I dont think thats right. Its 6 of one, or half dozen of the other. And ignore the high mpg , i was taking the picture while driving so was coasting downhill.

[MFL]

Hey, happy you are getting good mileage! Wished mine was better, closer to yours, but doesn't really matter to me. I didn't have good mileage in mind, when towing a big box! 🙂

Picture posting here is quite easy. You just need to google rv.net picture posting, and should take you to easy to follow instructions.

Jerry

[Sjm9911]

I also think having street tires help also, so not oversized aggressive treads. Like in idaD ram picture.

[Sjm9911]

That works too! Lol.
But I am serious about the millage,14.2 average over the last 400 miles. So, I do half highway and half city. Thats dictated by where I live. If the site was easier to post a pic, i would. The towing was averaged, over the last disney trip. So, 1200? Miles each way. It will also depend on the driver and if you ride the brakes I guess. But its a real figure. As close as I can tell.