MPG in 2010

[JHumphries]

By the way I bought a 2010 SLT Crew Cab Long Bed 4x4 6sp manual 3. 73 yesterday.

 

[TWood]

Quote:

[Originally Posted by [DF5152]

Ok how about this the truck gets better fuel economy at 70 in 5th gear then it does at 70 in 6th..... WHY?]







In order to keep the rpm in the maximum efficiency range of 2150 rpm, as recommended by cummins, you would have to cruise at about 87 mph in 6th gear (Automatic and 3. 73 gear ratio) or about 79 mph with 4. 10 gears. Cruising in 5th gear lowers those speeds to 66 mph and 61 mph to stay in the recommended range. These trucks are pushing so much air at the higher speeds that the fuel efficiency may never be very good in 6th gear.

 

[TWood]

First time i've tried to use a quote. How do you guys get that cool quote box?

Sorry kind of new at postingon this site.

 

[JHumphries]

First time i've tried to use a quote. How do you guys get that cool quote box?

Sorry kind of new at postingon this site.

Click on the 'Quote' button on the bottom of the post you want to quote.

 

[TWood]

Thats easy enough

Thanks.

 

[domehead]

I have standard 6 speed and in 5th gear which you will not run 70 mph maybe 55 and in 6th gear at 2150 rpm you are about 70 mph.



I am basing my information on the type of truck I own. Sorry that I did not see thatyou had the auto which it apepars to be better on the fuel.

 

[domehead]

Quote:

[Originally Posted by [DF5152]

Ok how about this the truck gets better fuel economy at 70 in 5th gear then it does at 70 in 6th..... WHY?]







In order to keep the rpm in the maximum efficiency range of 2150 rpm, as recommended by cummins, you would have to cruise at about 87 mph in 6th gear (Automatic and 3. 73 gear ratio) or about 79 mph with 4. 10 gears. Cruising in 5th gear lowers those speeds to 66 mph and 61 mph to stay in the recommended range. These trucks are pushing so much air at the higher speeds that the fuel efficiency may never be very good in 6th gear.

maybe you should fill your tank up have a 50 mile route planned out and run your truck in 5 th gear at highway speed than returning to the same station and top it off and hand calc the mpg. next do the same route only in 6th gear and hand calc again let us know the results.

 

[jjdiesel]

5th gear is 1to1 ratio... . in most cases will provide the best efficiency, (6spd manual)

 

[Vaughn MacKenzie]

5th gear is 1to1 ratio... . in most cases will provide the best efficiency, (6spd manual)

DF5152 probably has the 6-speed auto, which is 1:1 in 4th. 5th & 6th gears are both overdrive.

 

[jjdiesel]

Thanks Vaughn for clarification.

 

[domehead]

I would like to see the people with the autos to try the little test I posted to see which gear gets the best MPG. Than it would be even more intersting to see how the MPG is when the truck is loaded with trailer say with 12 of weight.

 

[DanPerry]

Breaj In

I just order a 2010 quad, shortbed, autotrans, 4. 10 gears and 6. 7 turbo. I am trying to get an idea of what to expect for GPM. I was running a Ford 7. 3 and the mileage was about 10 in town until about 20,000 miles then went to 16.



Just are other experiencing with the 6. 7



Dan

 

[domehead]

With 3. 73 gears and 6 speed standard I am getting about 16mpg hwy and 13 in town, with 8,500 miles on it.

 

[CUMMINZ]

It will take 15-20k miles on your engine before you will see the optimum mileage.



As to the wind resistance question: Every 10 miles an hour over 40 you go the resistance increases a bunch. Driving at 62 is much better than 70. Small amount is counted to rpm but much more is counted to wind resistance.

 

[DanPerry]

Thanks, that is what I was thinking. That what happened on my Ford 7. 3 one ton.



thanks again

Dan

 

[DF5152]

Well with 10k on the truck I took a recent trip 453 miles almost all highway got 15. 99 mpg. I think that sucks. all my pollution stuff is still attached. I used to get that around town with my last truck and I got alot of turbo lag.....

 

[DThweatt]

I'm at a high of 16. 7 all highway. and around 13. 8 in mixed driving. avg of 15. ( im logging it on a fuelly acct now)



auto/4x4/3. 73 I happy with it as the 08 ford I traded in was down around 11 on the highway.



just my perspective



I just towed my 2500# car hauler about 75 miles, then loaded up my 98 quad cab 4x4 on it (bout 10,000# total) and towed it home at 70 mph with the a/c on... I got 11. 2 mpg

 

[rscurtis]

You can thank the EPA (aka the Economic Punishment Agency) for this. My slightly modified '03 gets 22+ driving around in rural Pennsylvania, and the oil is still clean after 18,000 miles. So much for "reducing our dependence on foreign oil".

 

[Powder Extreme]

4200 miles on the truck, 2000 of it loaded or towing. Best ever was 14. 4mpg, empty running 75. Worst ever was 8. 4 pulling a 30' enclosed trailer weighing a measly 5k. I pulled the trailer on a 1600 mile trip varying speed between 75 and 60, 5th and 6th gear. 8. 4 was worst, 9. 7 was best. Not really much difference, and unacceptable in my book. This is the worst fuel mileage truck I've owned yet. 200 mile trip pulling my 38' 14k 5th wheel @ 70 - 75 10. 5mpg. I'm still scratching my head how the 30' bumper pull at almost a third the weight can generate even worse fuel mileage. I guess it isn't as aerodynamic as the 5th wheel.

Every tank of fuel calculated and logged. Overall statistics 10. 87 average, 14. 44 best and 8. 47 worst. (smartphone app)

 

[BILLUA]

4200 miles on the truck, 2000 of it loaded or towing. Best ever was 14. 4mpg, empty running 75. Worst ever was 8. 4 pulling a 30' enclosed trailer weighing a measly 5k. I pulled the trailer on a 1600 mile trip varying speed between 75 and 60, 5th and 6th gear. 8. 4 was worst, 9. 7 was best. Not really much difference, and unacceptable in my book. This is the worst fuel mileage truck I've owned yet. 200 mile trip pulling my 38' 14k 5th wheel @ 70 - 75 10. 5mpg. I'm still scratching my head how the 30' bumper pull at almost a third the weight can generate even worse fuel mileage. I guess it isn't as aerodynamic as the 5th wheel.

Every tank of fuel calculated and logged. Overall statistics 10. 87 average, 14. 44 best and 8. 47 worst. (smartphone app)

Well, considering these aren't even broken in until 20 k or so, the mileage is not surprising. If you are comparing your 02 to this, you also need to take into consideration the upped stock hp and torque. Plus, I'm not sure 3:42 with the auto are the best choice for towing. .

Nothing comes for free.