RAM 1500 Diesel Forum banner

21 - 33 of 33 Posts

·
Registered
Joined
·
15 Posts
Just filled up and my last tank breaks down like this. 50/50 City/Hwy - 554 miles driven, 30.049 gallons used, 18.437 MPG hand calculated. EVIC was showing 17.9 so I was pleasantly surprised the MPG was better. I'm starting to realize that many of the higher MPG responses on varying forums are likely in flatter areas versus where I live. City driving also affects my MPG more than I thought it would, but at the end of the day, the overall mileage capability of this truck is outstanding. I absolutely love my truck and now if I can find a good local service center. :)
 

·
Registered
Joined
·
13,214 Posts
Appreciate the real-world report.

Adding a note of caution. Guessing you have the 33 gallon tank or something close to that. Putting a full 30 gallons in there means you were down a bit. That fuel pump should not be run dry as air into the fuel system can take out the injector pump. Just something to think about.

Enjoy your new truck.
 

·
Registered
Joined
·
15 Posts
Appreciate the real-world report.

Adding a note of caution. Guessing you have the 33 gallon tank or something close to that. Putting a full 30 gallons in there means you were down a bit. That fuel pump should not be run dry as air into the fuel system can take out the injector pump. Just something to think about.

Enjoy your new truck.
Thanks for the heads up and I didn’t even think out that. I do have the 33 gallon tank and in your opinion, what is the lowest I should go down to? 1/4 or 1/3 of a tank?
 

·
Registered
Joined
·
37 Posts
Whatever the speed limit was , which for most of the trip was 70mph. The average was 65-75 other than a couple of slower roads and traffic thru Atlanta which slowed down some.
Just to clarify, mine is a crew cab 4x4. I have 3.21 gears and a decked toolbox filling the bed full of tools. I’m guessing the box and tools is around 500lbs and I have a 50lb tool bag and some odds and ends stud under the rear seat like a fire extinguisher.
 

·
Registered
Joined
·
13,214 Posts
Appreciate the real-world report.

Adding a note of caution. Guessing you have the 33 gallon tank or something close to that. Putting a full 30 gallons in there means you were down a bit. That fuel pump should not be run dry as air into the fuel system can take out the injector pump. Just something to think about.

Enjoy your new truck.
1/4 tank for me. Actually as an old offshore boating person I have lived the rule of thirds. 1/3 fuel out, 1/3 back and the rest for emergencies. You always want enough fuel in that tank to keep the pump cool and never, ever allow it to suck air as that can lead to major issues with the fuel pump. The CP4 in both the older Ecodiesel and the new ones is NOT tolerant of even a moment running dry.

When changing fuel filters prime, then prime some more. These are not like old tractor engines where you crack each injector to prime things.
 

·
Registered
Joined
·
13,214 Posts
Just to clarify, mine is a crew cab 4x4. I have 3.21 gears and a decked toolbox filling the bed full of tools. I’m guessing the box and tools is around 500lbs and I have a 50lb tool bag and some odds and ends stud under the rear seat like a fire extinguisher.
If you truly have a Gen 3 with 3:21 rear gearing can you post a picture of the speedometer and tach at speed?

Try to get it going say 60 mph or 70 mph on the speedometer and show the tach being sure you are in 8th gear. Many have spoken of the issue and few to none have proven it with a picture. Lots of the window stickers list the basic 3;21 ration at the start and neglect to print the 3:92 ration in the option area mandatory for the Gen 3 Ecodiesel.
 

·
Registered
Joined
·
37 Posts
If you truly have a Gen 3 with 3:21 rear gearing can you post a picture of the speedometer and tach at speed?

Try to get it going say 60 mph or 70 mph on the speedometer and show the tach being sure you are in 8th gear. Many have spoken of the issue and few to none have proven it with a picture. Lots of the window stickers list the basic 3;21 ration at the start and neglect to print the 3:92 ration in the option area mandatory for the Gen 3 Ecodiesel.
To be clear, my window sticker doesn’t show any gear ratio of any kind and I know the 3.92 is optional so I assumed there was no way I had one. Either way I’ll take a pic on my way back home tonight.
 

·
Registered
Joined
·
37 Posts
If you truly have a Gen 3 with 3:21 rear gearing can you post a picture of the speedometer and tach at speed?

Try to get it going say 60 mph or 70 mph on the speedometer and show the tach being sure you are in 8th gear. Many have spoken of the issue and few to none have proven it with a picture. Lots of the window stickers list the basic 3;21 ration at the start and neglect to print the 3:92 ration in the option area mandatory for the Gen 3 Ecodiesel.
 

Attachments

·
Registered
Joined
·
13,214 Posts
Went "nuts' digging way back in my picture file to see what the 3:55 rear end ratio I had did for rpm's at 70 mph. Well I found the exact picture taken when I bought it new and there was only 20 miles on the truck. This is NOT that picture but a much later one but close enough.

1AHMtQHgRIeTaCMRu6STVQ by Larry Malinoski, on Flickr

Seems that my 3:55 rear end did about 1,750 rpm at 70 mph. You seem to be doing about 1600 rpm. Truly you do NOT have a 3:92 rear end ratio unless there has been a change in the 8th gear ratio of the transmission. You just might have that 3:21 you speak of. That is in spite of the current information that only the 3:92 is available in the 2020 Gen 3.

Education. Thanks for the education. Enjoy the truck.
 
21 - 33 of 33 Posts
Top