2nd Gen Non-Engine/Transmission driving style does not affect MPG much !

[damon]

when I first got my ram nearly a year ago, I drove it rather mellow while trying to break it in and sub-consiously hoping to get the great mileage that many owners claim. This consistently resulted in 15. 5 mpg in a mix of freeway/town driving. Based upon reports I figured that this would improve once the engine had 10k + miles and loosened up.



Once I got the EZ, things became much more fun, and I found myself racing everything that is willing and really using this new found power more often than not. The result - mpg between 15 - 15. 5 consistently.



So last tank, with fuel prices as high as they are, I decided to do a test and drive like a granny for a tank. Nice slow acceleration, no speeds over 68, and no stop light racing. The result - 15. 8 mpg ! Same freeways/local roads as every other tank, but much different driving style. I was driving so slow that I thought for sure I would hit 17 mpg or so.



So if there's no $$ to be saved, and with all of the fun lost, it's back to the racing mode for me

 

[San Felipe Bob]

I am developing an adjustable manifold pressure indicator light , or light's.

It will be set by the driver to lets say something like 8 or 10 psi.

When you get on the throttle too hard (for good fuel milage)the L. E. D. light's up. The light mounted somewhere on the dash or like mine next to the boost gauge.



My CTD builds boost so fast it's hard to keep tabs on the gauge and watch the road(especially out here in So Cal. )



I'm also building a magic box.

This box will "read" the input of your existing EGT probe,and manifold pressure.

the box will have outputs for mutiple LED light's.

and inputs for EGT and manifold pressure. The light's will be fully adjustable by the driver as needed (like higher values when towing than when empty.



My idea is to alert the driver of high EGT's before they get to the max temp and when they get to the max temp .

A stepped system an inteligent dumby light if you will.



I'll post the info on here when i get the prototype finished.

Still have lots of bugs to work out.



SFB

 

[Berrigan]

I agree. Granny or hot doggin only changes my mpg 0. 5 to 0. 75. What does lower it the most is towing at high speed, using the ac in the summer. and extended idle time.



That means it costs you nothing to blow away a furd once in a while.

 

[CFAR]

damon,

From cummins website:



How many miles does the Cummins engine require for break-in?



In general, 5000 miles. This depends on the type of driving the truck is subject to; hauling or towing a load will shorten the break-in period. Light duty hauling or "babying" the engine can delay full engine break-in for up-to 20,000 miles.



How many miles do you have on your truck?

Mine did not really start getting good mpg until about 18000



How are the auto transmission guys with built trannys doing?

Bette with upgrades or worse?

 

[damon]

I have just over 13000 on it now, and although the load was light - about 5000# - it was towing my trailer and gear after 100 miles of empty driving right off the dealer lot. I had to buy the truck while on vacation with my 5th wheel after the old truck died a painful death, and I wasn't sure that this was a great way to break it in, but many TDR members said that was a perfect way to break in the Cummins. Most of the miles since have been empty, so I'm sure that it is not completely broken in quite yet.



I just get this feeling that I'll never get better than 16 - it's a 4x4 with a solid axle and auto transmission, and given the weight of the truck I'm pretty happy to get 15-16 with my foot into the pedal and having fun.

 

[jkern]

me too...

damon



i agree with you 100%. my 99 is the same way and i have asked the TDR lots of times why i get consistant yet low milage as compared to some. i think that it is the nature of some of the trucks. i never believed anybody that said they got over 17. 5mpg with a dodge cummins until my brother got a 2001 and he consistantly gets 20-21mpg traveling and 18 or so in town. guess i have to see it with my own eyes... but i would like to know why individual trucks vary so much and why i am a lucky person to be stuck with one that only gets 15mpg... on a good day. i get as low as 13 just running around empty :{ :{ :{

 

[pwr2tow]

Some have said it takes 40,000-50,000 miles before the engine breaks in. Well I was very skeptical of this claim but have a story to tell.



Last fall when the weather started to turn cold my truck started to run quieter, keep in mind the colder it gets the louder the truck rattles, below zero temperatures would make the engine sound like it was comeing through the hood. I didn't think too much of it at first since I had 48,000 miles on the truck but then I remembered some saying it takes up to and some times beyond 50,000 miles for the engine to break in. I observed the engine noise all winter and at 50,000 miles and 25 degrees below zero the engine ran almost as quiet as in the summer. The fuel mileage has improved for winter driveing and winter blend fuel which use to be 14. 5 MPG and now up to 15. 5 and 16 Mpg which use to be my summer fuel mileage. I can not wait for summer weather and straight #2 fuel to see if my summer fuel mileage has got better. The more I think about it I did get one tank of fuel before the cold weather set last fall that did net almost 18 MPG, I thought it was a fluke, maybe, maybe not.



A little information about my driveing habits. I don't drive like I stole the truck but I don't drive around from stop signs under 16 PSI of boost either, stop signs in rural areas not stop lights in cities. I tow alot with my truck and towed since it had 500 miles on it. I hope what I am seeing is real but more time, fuel consumed, and miles will net more real results.



There is one thing I did do a few summers back that did net me 2. 8 miles per gallon more while towing but had no effect on the non towing mileage, I changed the I. A. T. sensor, I credit this one to the findings of Marco.



As far as I know no one has figured out why one truck gets 14-16 MPG, the next 16-18 MPG and the next one gets 20-22 MPG on similarly equipped trucks, this doesn't seem right especially on an electronically controlled engine.



Now that your all sleeping I'll quietly move onto the next thread.

Thanks for listening.



Ron

 

[San Felipe Bob]

Math

My 97 CC 4x4 auto with 3:54's got great #'s right off the lot!

Then one day I checked the Odometer against 1 of those mileage indicator's along the side of road.



Ut oh with the stock rims and tires the odo was way off.

the speedo was off too.

When I changed to the 33 12. 50's tires.

The odo and speedo were spot on!



My guess is the the math and the calibration of the speedo's that make the difference between the trucks.



By my calculation's I get 13. 8 mpg in stop and go So. Cal freeway driving. Plate and afc all the way forward(lots of smoke! )



And about 15 to 16 highway at 80 mph. with a light weight camper that is 12" above the cab. (big wind brake).



Mileage is 17 to 18 when I drive 55 mph but I was only able to go that speed once.





SFB

 

[damon]

good idea, and this may be the case for many folks. I tested my speedo against my GPS and mile markers, and it is right on with the 265/75's that came on my truck. I'm expecting to do a little better on mpg once I get bigger tires - unless the added drag offsets the added distance per rotation.