I know my heavy 19.5's are dragging my milage down, but what else works?

Well... Read this...

MPG_Secrets_Whitepaper.pdf

About the best one for economy is to duct tape a raw egg to your skinny pedal. That way you don't push on it to hard.......

Speed is the biggest killer...

http-~~-//www.youtube.com/watch?v=SRQdoPs_tLo

Calc: Speed / GPH = MPG

Oversized tire which you know... (Adds to the rotational mass. For every 4 pounds you drop you'll gain 1 HP)

Underinflated tires...

Aggressive treads have high rolling resistance...

Large frontal area (Lift kits & larger tire create more frontal area)

High cetane fuels... (Lower BTU content)

Using cetane booster or injector cleaners (lower BTU content)

Too large of injector...

Excessive weight... (Don't haul around extra weight for no reason).

I like to get good fuel mileage with my truck. I usually get 23.5-24.5 mpg during both the summer and winter. I credit this to using the A/C in the summer and using winterized fuel in the winter. I do see better numbers during the fall and spring sometimes a low to mid-25 mpg. I credit that to not using the A/C as often. Speed is the biggest killer. I usually never drive faster than 62 mph. If I drive 70 mph and pass indiscriminately my mileage drops to 22 mpg. Oversized tires kill your fuel mileage, your power, and your brakes. Tires are basically 4 large flywheels that you have to spin up every time you take off. And taller tires require more brake pressure on the linings to stop the same distance as a OEM tire. There's a mathematical formula that applies to flywheels that looks similar to but not exact, Kinetic Energy = 1/2 mass x radius squared. The point of this is that the kinetic energy and inertia energy applied to spin up the taller "radius" height of the tire is squared (multiplied times itself) This 'spin up energy' could be put to better use to propel you down the road by using a shorter tire. Larger tires increase the frontal area of the vehicle thus creating more drag. There's a mathematical formula for that: Drag= 1/2 frontal area x Velocity squared x the drag coefficiency. The point of this is that as you increase your speed, this factors in much more on the air resistance than whether you have increased the frontal area by installing a leveling kit to the front of your truck. I agree with all the things that Mopar1973Man has presented here. Mostly it is speed, but these are other principles to consider as contributors to the subject, the tires aka flywheel's inertia and kinetic energy and aerodynamics and the brake specific fuel consumption of the engine. http://forum.mopar1973man.com/attachment.php?attachmentid=3070&stc=1 In this example chart for a industrial 5.9L Cummins the fuel curve indicates this engine is most efficient close to 1600-1700 rpm. It just happens that 1650 rpm is just about 54.5 mph in my truck using the factory original tires, if my math skills serve me well. Just adding this to information, but all these things and more have been mentioned already. I believe two things that can help would be having a pyrometer and manifold pressure gauge to monitor. I personally do not have a pyro as of yet, but it will be my next addition. Knowledge is power.

Stanlee1963, Great post and info.. Maybe I missed your signature, but, if you don't mind could you tell us a little bit about your truck.

1997 clubcab, 2 tone - Drk Chestnut Prl and Driftwood Satin Met. 386K miles, 5spd, 3.54, OEM size rubber, boost gauge, muffler delete. The #11 fuel plate, AFC housing and starwheel all the way forward. 23.5-24.5 mpg with the A/C on 100% of the time.

I am trying to search my memory and I was thinking this specific engine (EBQ210-20) was used for low speed application industrial equipment. Gen sets, earth movers, dump trucks etc. Was this engine also put in the early diesel pickups? Is this the engine that is in your 97?The 24v vp44 engines have the most efficient bsfc at about 2000 rpm and I was thinking the 12v version in the pickups was similar to this rpm level, but I am not absolutely sure of that. Many of the 12v's get good mileage at the 70mph + speed range.I have the 3.55s and I have to go about 73mph + to get the rpms up to 2000. I am guessing that the manual shift versions of the 12v and 24v are up in the mid to high 70's to get to this rpm (with 3.54/3.55 gears).Therefore, not accounting for any other types of gains or losses, running the engine near 2000 rpm should result in the most economical mode for the truck. But you can't argue with 23 to 25 mpg.

my 02 sees 71mph at 2k rpm.

I agree that at 2000 rpm the 5.9 has an efficient bsfc, especially true with the all the 24v and the 6.7s. The EQB210 example I used was a poor choice. To validate your statement, I will say that at 2000 rpm my truck runs 66mph and still gets a high 22 or lower 23 mpg. But of course my truck gets better MPGs with decreased speed irregardless to the BSFC. Referring back to Mopar1973Man's 'secret whitepages' posted on this thread. To increase speed, you have to increase the amount of fuel to overcome the resistance. (Speed is the master key to increasing your fuel mileage. I think about my truck going up a hill like it was me running bleachers. If I walk the bleachers it is no big deal, but if I try to run the bleachers I would get short of breath pretty fast. The more speed you demand out of something, the more fuel is demanded.) Thanks for the conversation and keeping me real about the EQB210... I had used it only because it was of similar power rating to my pu.

I am trying to search my memory and I was thinking this specific engine (EBQ210-20) was used for low speed application industrial equipment. Gen sets, earth movers, dump trucks etc. Was this engine also put in the early diesel pickups? Is this the engine that is in your 97? The 24v vp44 engines have the most efficient bsfc at about 2000 rpm and I was thinking the 12v version in the pickups was similar to this rpm level, but I am not absolutely sure of that. Many of the 12v's get good mileage at the 70mph + speed range. I have the 3.55s and I have to go about 73mph + to get the rpms up to 2000. I am guessing that the manual shift versions of the 12v and 24v are up in the mid to high 70's to get to this rpm (with 3.54/3.55 gears). Therefore, not accounting for any other types of gains or losses, running the engine near 2000 rpm should result in the most economical mode for the truck. But you can't argue with 23 to 25 mpg.

ok guys yall have to tell me what BSFC is. i do appreciate all of the technical data that alot of folks post here, but it is usually over my head. but dont stop on my account. if i can learn something it is a plus.

Brake Specific Fuel Consumption (or BSFC) is the ratio between the engine's fuel mass consumption and the crankshaft power it is producing.It the most efficient operating range of the engine only. The most power for the least amount of fuel being used.The curve shape is similar to a bath tub. The coordinates on the BSFC chart are fuel consumption and RPM. (see attached chart)Anything slower or faster will use more fuel. Remember this BSFC is efficiency of the engine only. Your mileage may vary due to lots of other parameters (i.e. tires, load, aerodynamics, friction losses, etc., etc. etc.)

Dodge Ram BSFC Chart.pdf

i take it the ect, ect , ect would include my foot. the right one especially. i made one run recently between 65 and 70 for about 450 miles and was able to get 20 mpg. my normal driveing i usually get 18. for a 7k pound truck i am not complaining. my last dodge had a V10. 12 mpg on the highway with a tail wind. gas was .95 a gallon then. glad i dont own it any more. i do appreciate the info. i have learned something today.

I like this 24v chart. In fact I think it's on my flashdrive. I like BSFC charts and have stared at them since the 1980's for various engines, caterpillar, mack, cummins, detroit series 60. The BSFC is an good indication of the efficiency of a particular engine at full throttle only. BSFC charts can assist one in specing a truck to have proper gearing with a balance of power and economy. Using the proper gearing, an engine designed to have a low BSFC at 2000rpm allows good highway cruise speed while providing its best efficiency. This is especially true while pulling a heavy load. But when you are not fully loaded, please know that traveling at a reduced rpm/speed (such as 54-62 mph) is going to yield a better MPG than setting your cruise so that you are at 2000 rpm. Increased speed, requires more energy. Reduced speed, reduces power demand, reducing fuel usage. No matter if we use my industrial BSFC chart or your 24v chart.

Brake Specific Fuel Consumption (or BSFC) is the ratio between the engine's fuel mass consumption and the crankshaft power it is producing.

It the most efficient operating range of the engine only. The most power for the least amount of fuel being used.

The curve shape is similar to a bath tub. The coordinates on the BSFC chart are fuel consumption and RPM.

(see attached chart)

Anything slower or faster will use more fuel. Remember this BSFC is efficiency of the engine only. Your mileage may vary due to lots of other parameters (i.e. tires, load, aerodynamics, friction losses, etc., etc. etc.)

The way to best mpg is to start with the right gear ratio... which my 4.10 is NOT. I am optomistic that my little mods have bumped mpg. Honestly, the best way to wring the mpgs out is to drive with a feather touch of the skinny pedal. Coast, foot off when you can rather than keep power on. Anticipate the crest of hills & gradually back off throttle. Coast into a stop, minimize the brake use. I routinely get 1-1.5 mpg more than when wifee drives the truck (I'm not a happy camper when she does but what are you going to do if you like sleeping indoors?) My overheard display was right on until I installed the xzt+... once I managed 19. Most often in 17-18 range... running light.

Hamilton cams just made a fuel mileage cam. http://hamiltoncams.com/index.php?id=2&type=current

Using a driving technique to achieve better fuel mileage is a modification as far as I am concerned. Modifying the driver's performance vs. the equipment. Using this driving technique you described so well is how I routinuely get my 23.5-24.5 mpg with the A/C on. I do watch my boost gauge and try to keep the boost low on flat ground and attempt to keep it at that same low pressure on the hills by gradually backing off the throttle about 1/2 the way up the hill exactly as you described it. You described it better than I could, but it is the way that I drive.

The way to best mpg is to start with the right gear ratio... which my 4.10 is NOT. I am optomistic that my little mods have bumped mpg. Honestly, the best way to wring the mpgs out is to drive with a feather touch of the skinny pedal. Coast, foot off when you can rather than keep power on. Anticipate the crest of hills & gradually back off throttle. Coast into a stop, minimize the brake use. I routinely get 1-1.5 mpg more than when wifee drives the truck (I'm not a happy camper when she does but what are you going to do if you like sleeping indoors?) My overheard display was right on until I installed the xzt+... once I managed 19. Most often in 17-18 range... running light.

So whats the sweet spot for 12v, I can get 21-23 at 1725 rpms at 65.Sent from my mobile phone using tapatalk

Shoot I was shocked after taking my trip with the RV. I even weighed the setup...Truck Front - 4040#Truck Rear -- 4280#RV ----------- 7760#Total ------- 16080#When I did my MPG hand calc'ed... 14.13 MPG...

So whats the sweet spot for 12v, I can get 21-23 at 1725 rpms at 65. Sent from my mobile phone using tapatalk

Duz a 95 have the OBDii port under the dash for a Scan Gauge II?

Duz a 95 have the OBDii port under the dash for a Scan Gauge II?

Yes and No... Yes there is a OBDII port but no you'll not capable of using the ScanGauge II for the other feature like MPG's and trip data. Because there is no connection to the p-pump for fuel data. But being 95 I'm not sure if is truely a OBDII port or a OBDI port since 96 was the starting year for OBDII..