Ford/Chevy mileage

Here's some data from tests. Now I do have an issue with these in diesels as they are like 100 mile runs. And that doesn't take into account regens and such. Or how often. I think you need to do 5,000 mile runs but they'll never be able to do that.


http://news.pickuptrucks.com/2017/08/whats-the-best-one-ton-heavy-duty-pickup-for-2017.html

http://news.pickuptrucks.com/2017/05/whats-the-best-34-ton-premium-truck-for-2017.html

http://special-reports.pickuptrucks.com/2014/08/ultimate-one-ton-hd-challenge-fuel-economy.html

Cummins12V98 wrote:

transamz9 wrote:
Personally I don't thing fuel mileage will be measurably differ between 3.31 and 3.55 with the flat torque curves of today's diesels. I cant see a whole lot of difference with my 3.42's when running in 5th as opposed to 6th.

Towing with my 11 HO Dually with 3.42's I determined I was SLIGHTLY better mileage towing in 5th and for sure better in 6th solo.

I'm definitely better in 6th running solo at 65-85 on interstates but local highways up to 60 there's very very little difference that I've found. When towing I always run TH mode and my truck will not shift into 6th until 65 or above. Once you get it in 6th it will pull pretty hard down to around 60 or so before it drops back to 5th.

transamz9 wrote:
Personally I don't thing fuel mileage will be measurably differ between 3.31 and 3.55 with the flat torque curves of today's diesels. I cant see a whole lot of difference with my 3.42's when running in 5th as opposed to 6th.

Towing with my 11 HO Dually with 3.42's I determined I was SLIGHTLY better mileage towing in 5th and for sure better in 6th solo.

We usually get 11 mpg towing a combined 22920 lbs. Have done better on a certain day and weather on a one day check on I-5 in California. 2001 8.1 dually also had the best mileage years ago on this same area.

chevman

Back to the question, my 2012 GMC D/A combo crew-cab will get around 12 mpg pulling my 30' FW and 19" aluminum boat together. On the highway at around 70 mph, we will get between 18 and 19 mpg. I haven't never owned a Ford Diesel so can't help you with the Ford mpg, but others have.

4x4ord wrote:
I understand gear ratios and tire diameters perfectly. What I don't understand is why there is as much difference in fuel economy between the 3.31 trucks with 18" rubber and the 3.55 trucks with 20" rubber as there is. But from experience I know there is a big difference. As well because the owners manual states 20% less mileage per tank of def under normal driving conditions is expected with the 3.55 axle vs the 3.31 I will state again that I won't be surprised if something is different in the fueling softeare between the different axle ratio trucks.

Combined tire/wheel combo weight and tread pattern can play a role. If the total circumference is identical or very close I cannot see different programming simply from a cost standpoint. But event with similar outside dimensions the tires will still behave differently with different size wheels.

I understand gear ratios and tire diameters perfectly. What I don't understand is why there is as much difference in fuel economy between the 3.31 trucks with 18" rubber and the 3.55 trucks with 20" rubber as there is. But from experience I know there is a big difference. As well because the owners manual states 20% less mileage per tank of def under normal driving conditions is expected with the 3.55 axle vs the 3.31 I will state again that I won't be surprised if something is different in the fueling softeare between the different axle ratio trucks.

Since Ford chooses the tire size that goes with the wheels they offer, it doesn't matter how you describe it. Ford doesn't "offer" different gear ratios, they install the ratio that gets the end result they want. In the case of the F250 and F350 SRW models only the snow plow package will get you a different RPM at any given road speed.

Personally I don't thing fuel mileage will be measurably differ between 3.31 and 3.55 with the flat torque curves of today's diesels. I cant see a whole lot of difference with my 3.42's when running in 5th as opposed to 6th.

FishOnOne wrote:

Lynnmor wrote:

Grit dog wrote:

Lynnmor wrote:

4x4ord wrote:

What you are saying is not true. I don't understand all of the difference between 3.55 and 3.31 gearing

That right there is the problem. I tried to help, but you would do well to read the manual before discrediting others.

You'd do well to think before typing as well.
In your previous post you alluded that the different gears were negated by different tire sizes! That would make no sense to offer different gearing then.
Plus you inferred that the rim diameter somehow affects rolling diameter. (Because rim size doesn't have a dang thing to do with gearing or mileage. )
There are no different injection cycles either.

More silly rvnet babble....

It is hard to believe that there are those that cannot understand that tires of a larger circumference coupled with gearing that is lower by the same percentage gives an end result that is the same. Childish remarks show an even greater lack of intelligence.

Well said....

One is saying rim size and one is saying tire size. They are both right.rim diameter has nothing to do with gear ratio if the tire diameters are the same with both unless you are running with flat tires.