Ram 3500 MPG test

[Travlingman]

The Ram MPG test video. Wasn't expecting that big a difference.

[Cummins12V98]

That is a good idea. I would have towed today but in fortunately my four day handgun safety course in Pahrump, NV is cancled. GRRRRR

When I head North May 1 I will experiment.

[4x4ord]

Cummins12V98 wrote:

4x4ord wrote:

Cummins12V98 wrote:

4x4ord wrote:

Cummins12V98 wrote:
4X I did lockout 6th on my 11 DRW with 3.42’s. On flat ground the mileage was the same at 62. It performed better overall leaving it in 5th. No down shifting on hills that way.

Mor important would be to know what my RAM would be turning if I had the same geared trans as the Ford 10 speed with my 4.10’s at 70 mph.

I'm not understanding what you're asking. The Ford 10 speed has a .632:1 gear ratio in 10 th gear .... same as your Aisin in 6th. So if you swapped the 10r140 for your Aisin it wouldn't change your 70 mph engine rpm.

Ah I did not know that. I assumed it would have been running lower rpm than mine.

So one more question. Did the ford have 4.10’s?

The Ford had 3.55 gears and slightly smaller tires .... 31.5" vs 31.8" for the Ram.

Makes sense that it would get better mileage at 70 turning less rpm than I at 2,000.

Supports my logic that after owning a 11 DRW with 3.42's and now 4.10's I would buy 3.42's and AISIN even towing my 35k combined.

If the RAM had 3.42's on the test it would most likely get similar mileage if tests were ran the same day.

How much do you think lowering your rpm while towing heavy from 2000 to 1670 is going to save you on fuel?
You can get an idea with your unit .... When you're towing heavy simply set the cruise at about 60 mph (about 2040 rpm) in 5th gear for a while and use your trip odometer to measure your fuel economy, then leaving the cruise set at 60 shift into 6th and let the engine drop down to 1670 rpm and reset your trip odometer to measure your fuel economy. If you test over the exact same section of highway you'd only have to measure for a few miles each time and you'll have a very good idea. (Even if the trip odometer isn't 100% accurate it should be out about the same % both times)

[Cummins12V98]

4x4ord wrote:

Cummins12V98 wrote:

4x4ord wrote:

Cummins12V98 wrote:
4X I did lockout 6th on my 11 DRW with 3.42’s. On flat ground the mileage was the same at 62. It performed better overall leaving it in 5th. No down shifting on hills that way.

Mor important would be to know what my RAM would be turning if I had the same geared trans as the Ford 10 speed with my 4.10’s at 70 mph.

I'm not understanding what you're asking. The Ford 10 speed has a .632:1 gear ratio in 10 th gear .... same as your Aisin in 6th. So if you swapped the 10r140 for your Aisin it wouldn't change your 70 mph engine rpm.

Ah I did not know that. I assumed it would have been running lower rpm than mine.

So one more question. Did the ford have 4.10’s?

The Ford had 3.55 gears and slightly smaller tires .... 31.5" vs 31.8" for the Ram.

Makes sense that it would get better mileage at 70 turning less rpm than I at 2,000.

Supports my logic that after owning a 11 DRW with 3.42's and now 4.10's I would buy 3.42's and AISIN even towing my 35k combined.

If the RAM had 3.42's on the test it would most likely get similar mileage if tests were ran the same day.

[ShinerBock]

alboy wrote:
OUR 15 dually with asin and 3:42 pulling a Landmark at approx 17500 at 70 gets worst mileage in 6th at 1650rpm then pulling in 5th at 1975 rpm.Best mileage is keeping it under 70 and 2000 rpm,seems to tow best at 68 with few downshifts

My 14 does too if I am towing 70 mph or below. I was amazed at the fuel mileage difference between the two gears. I thought it was be less than 1 mpg, but was surprised when it was more than that with both my gooseneck cattle trailer and 5ver. In fact, it tells me to use the ERS to select gears to lower gears for optimum performance/efficiency and to extend the transmissions life under tow tips in the owners manual.

[alboy]

OUR 15 dually with asin and 3:42 pulling a Landmark at approx 17500 at 70 gets worst mileage in 6th at 1650rpm then pulling in 5th at 1975 rpm.Best mileage is keeping it under 70 and 2000 rpm,seems to tow best at 68 with few downshifts

[4x4ord]

Cummins12V98 wrote:

4x4ord wrote:

Cummins12V98 wrote:
4X I did lockout 6th on my 11 DRW with 3.42’s. On flat ground the mileage was the same at 62. It performed better overall leaving it in 5th. No down shifting on hills that way.

Mor important would be to know what my RAM would be turning if I had the same geared trans as the Ford 10 speed with my 4.10’s at 70 mph.

I'm not understanding what you're asking. The Ford 10 speed has a .632:1 gear ratio in 10 th gear .... same as your Aisin in 6th. So if you swapped the 10r140 for your Aisin it wouldn't change your 70 mph engine rpm.

Ah I did not know that. I assumed it would have been running lower rpm than mine.

So one more question. Did the ford have 4.10’s?

The Ford had 3.55 gears and slightly smaller tires .... 31.5" vs 31.8" for the Ram.

[Me_Again]

blofgren wrote:

4x4ord wrote:
^^^^ Honesty I don't have a problem with the fill technique that was used. I used to check my fuel economy on every tank with my 2011 Ford, filling that same method, and got very consistant results. As long as you fill using the same method at the beginning and end of your trip there shouldn't be a problem with their method. But, I am surprised at the difference. If it had been the other way ... ie, if the Ford had burned 30% more fuel than Ram, there is a very good chance I would end up with a goat in my garage. I would at least be doing my own mpg check before buying.

I'm not sure that the fuel economy difference matters much when trading every couple of years....:B

If I had wanted better mileage I would have kept the 2001.5 RAM and the 29' Cardinal 5th wheel. To be truthful the 2015 gets much better than the toy we sold to by it.



Two B150 Cummins burned 3 GPH combined at 8 knots. Or 2.66 KPG or 3MPG.

[blofgren]

4x4ord wrote:
^^^^ Honesty I don't have a problem with the fill technique that was used. I used to check my fuel economy on every tank with my 2011 Ford, filling that same method, and got very consistant results. As long as you fill using the same method at the beginning and end of your trip there shouldn't be a problem with their method. But, I am surprised at the difference. If it had been the other way ... ie, if the Ford had burned 30% more fuel than Ram, there is a very good chance I would end up with a goat in my garage. I would at least be doing my own mpg check before buying.

I'm not sure that the fuel economy difference matters much when trading every couple of years....:B

[Me_Again]

4x4ord wrote:

For MeAgain to speed up from 60mph to 65 mph towing his TT to get better fuel economy.... well, I believe that he believes that.

Read it again. I was able to run 6th gear vs 5th gear. And yes hand cal mileage improved.



I was very surprise to find towing at 16K combine with the trailer above was almost the same mileage towing at 24,500 with the trailer below when towing at the same 60MPH in 5th gear.



Couple three things might have been in play. The 5th wheel was much closer to the cab to help push air flow over it. The 5th wheel has LRG all steel tires with low rolling resistances. The 5th wheel has a curved rear cap to bend air flow around the rear.

5th wheel was listed at 13'3" and TT at 11'2".

[4x4ord]

ShinerBock wrote:



I was commenting on this "There is always people claiming they lock out high gear while towing and don't see any loss in mileage. I've never believed these claims..." Believe it or not, you can gain fuel economy by using a shorter gear ratio depending on your speed, load, and the engine's sweet spot. Even the Ford engineer agrees.

And yes, per Cummins, the 6.7L's sweet spot is 1,900-2,100 rpm, not 1,700.

I could have worded that better. When Ron is pulling his Mobile Suite I can see it being an advantage to lock out 6th with 3.42 rear gears and not notice a loss in fuel economy. For MeAgain to speed up from 60mph to 65 mph towing his TT to get better fuel economy.... well, I believe that he believes that.

[Cummins12V98]

4x4ord wrote:

Cummins12V98 wrote:
4X I did lockout 6th on my 11 DRW with 3.42’s. On flat ground the mileage was the same at 62. It performed better overall leaving it in 5th. No down shifting on hills that way.

Mor important would be to know what my RAM would be turning if I had the same geared trans as the Ford 10 speed with my 4.10’s at 70 mph.

I'm not understanding what you're asking. The Ford 10 speed has a .632:1 gear ratio in 10 th gear .... same as your Aisin in 6th. So if you swapped the 10r140 for your Aisin it wouldn't change your 70 mph engine rpm.

Ah I did not know that. I assumed it would have been running lower rpm than mine.

So one more question. Did the ford have 4.10’s?

[ShinerBock]

4x4ord wrote:

ShinerBock wrote:

4x4ord wrote:


To get an idea as to what the 10 speed would do for the Cummins all you'd have to do is drive your Ram down the road towing a heavy load at 1700 rpm in high gear and reset your milage meter...... drive a few miles and see what your average trip mileage was. Then go back and drive the exact same stretch of road at the same speed in 5th gear (about 2095 rpm) and see what your trip meter says for mpg. There is always people claiming they lock out high gear while towing and don't see any loss in mileage. I've never believed these claims, but at the same time I don't think the increased fuel usage is going to be anywhere near 30%.

The same way a shorter rear gear ratio will provide better fuel economy when loaded, so will will a shorter trans gear when loaded. Don't believe me then ask a Ford engineer.

"Also consider that the axle ratio is only a portion of the overall pickup gearing. Manufacturers spend a lot of effort on powertrain matching. "Powertrain matching is really a systems approach," says Dennis Slevin, vehicle engineering manager, Ford Commercial Vehicles. "It is the engine, transmission, axles and tires working together. It is the effective ratio of engine power transmitted all of the way through the drive system to the ground."

He adds, "From our perspective there are interconnected reasons to choose optional axle ratios -- if you are hauling heavy loads with large trailers in hilly terrain, and you do a high frequency of towing." Consider a PowerStroke 6.7-liter diesel that offers a choice of a 3.31, 3.55, 3.73 or 4.30 axle ratio. "The 3.31 might be capable of towing the trailer. But if you are towing the majority of the time, you probably want the 3.55 because it will tow better and provide better fuel economy loaded.""


How to Pick Pickup Truck Axle Gear Ratios to Improve Performance

If you are in to high of a gear and "lugging" the engine to overcome the load, then the engine is not operating efficiently. The most efficient rpm is always changing based on speed and load. Towing 7-14k at low speeds of 60-70 mph, then it is best to lockout 6th to keep you at more efficient rpms. At speeds above 70, the 6th becomes more efficient.

I understand this stuff very well. As a rule for any speed you are travelling the highest gear the engine will pull the load in is the gear that will give you the best fuel economy. There might be some isolated segments in an engine's lower rpm range under certain power demands where running the engine a little faster might gain you 3 or 4% better fuel economy. The Cummins engine might like 1900 rpm better than 1700 pulling a load like TFL was pulling. If one rpm is going to be better than the other it's not going to be better by a very significant margin.

I was commenting on this "There is always people claiming they lock out high gear while towing and don't see any loss in mileage. I've never believed these claims..." Believe it or not, you can gain fuel economy by using a shorter gear ratio depending on your speed, load, and the engine's sweet spot. Even the Ford engineer agrees.

And yes, per Cummins, the 6.7L's sweet spot is 1,900-2,100 rpm, not 1,700.

[4x4ord]

ShinerBock wrote:

4x4ord wrote:


To get an idea as to what the 10 speed would do for the Cummins all you'd have to do is drive your Ram down the road towing a heavy load at 1700 rpm in high gear and reset your milage meter...... drive a few miles and see what your average trip mileage was. Then go back and drive the exact same stretch of road at the same speed in 5th gear (about 2095 rpm) and see what your trip meter says for mpg. There is always people claiming they lock out high gear while towing and don't see any loss in mileage. I've never believed these claims, but at the same time I don't think the increased fuel usage is going to be anywhere near 30%.

The same way a shorter rear gear ratio will provide better fuel economy when loaded, so will will a shorter trans gear when loaded. Don't believe me then ask a Ford engineer.

"Also consider that the axle ratio is only a portion of the overall pickup gearing. Manufacturers spend a lot of effort on powertrain matching. "Powertrain matching is really a systems approach," says Dennis Slevin, vehicle engineering manager, Ford Commercial Vehicles. "It is the engine, transmission, axles and tires working together. It is the effective ratio of engine power transmitted all of the way through the drive system to the ground."

He adds, "From our perspective there are interconnected reasons to choose optional axle ratios -- if you are hauling heavy loads with large trailers in hilly terrain, and you do a high frequency of towing." Consider a PowerStroke 6.7-liter diesel that offers a choice of a 3.31, 3.55, 3.73 or 4.30 axle ratio. "The 3.31 might be capable of towing the trailer. But if you are towing the majority of the time, you probably want the 3.55 because it will tow better and provide better fuel economy loaded.""


How to Pick Pickup Truck Axle Gear Ratios to Improve Performance

If you are in to high of a gear and "lugging" the engine to overcome the load, then the engine is not operating efficiently. The most efficient rpm is always changing based on speed and load. Towing 7-14k at low speeds of 60-70 mph, then it is best to lockout 6th to keep you at more efficient rpms. At speeds above 70, the 6th becomes more efficient.

I understand this stuff very well. As a rule for any speed you are travelling the highest gear the engine will pull the load in is the gear that will give you the best fuel economy. There might be some isolated segments in an engine's lower rpm range under certain power demands where running the engine a little faster might gain you 3 or 4% better fuel economy. The Cummins engine might like 1900 rpm better than 1700 pulling a load like TFL was pulling. If one rpm is going to be better than the other it's not going to be better by a very significant margin.

[Me_Again]

Real world empty run for Los Wages to Denver. Average speed was 70 MPH and 80 in some stretches. 15 MPG My SRW with 3.42 would have been around 19 MPH or a little higher. https://www.youtube.com/watch?v=9sFgt4rkLBg