14-15 in town (depends on time of year), 18-19 highway (on flat ground) @ 75.

 

Sorry John my bad for assuming people understood the crankcase joke. What I ment was if you got that much of a change in MPG then you stopped a major fuel leak that was going into your pan! Most trucks with loose tubes won't even run and will make alot of oil if they do! That means diesel getting mixed with your engine oil eventually filling your crankcase. Man that snow must really be deep by you to be that pissed off!

 

 

nah its ok. I'm sorry to you dangerous1965. U know how working on these things make u mad. LOL

 

No worries now let's fix some trucks! NEXT!!

 

Im on the hunt for better mpg. 2007 5.9 QC 4X4, Should recieve my smarty tomorrow. torque tube removed, 5inch mbrp turbo back exhaust, K&N filter installed.

I have heard that higher hp injectors would improve mpg due to better attomization of fuel. Is this the case?

Would a set of larger dia tires effectively reduce engine rpms at 70 mph maby keep it below 2K rpms? How big are we talking?

 

smarty with added timing should help considerably. and as far as I know, a set of 70-90 hp injectors are supposed to help mileage out 1-2mpg, as long as you dont abuse the newfound power too much

Well a set of bigger tires will reduce RPMs at 70 buttttttttt........ its going to make your engine work harder (more tire to turn) so bigger tires will probably decrese mileage slightly.

 

I get about 18-20 pretty much all the time.

 

Taking notes here since my '05 3500 auto, gets 14mpg on average hand calculated. Only mods are intake and thermostat removed. I went ahead and had all the fluids changed, replaced the thermostat and decided to keep it under 70mph. Smarty Sr is next on my list. (already have gauges being installed as we speak)

 

Just curious why did you remove your thermostat? And did your engine run very cold?

It is my understanding that if your engine is running cold, it will hurt your mileage. Im basing this statement off of an article Diesel Power did on a max MPG run with a 97 12 valve. They actually bumped up the temp of the engine to 210 degrees in an attempt to get better mileage.

And besides all that I know mine runs better once its warm