Hi im new on here and was wanting some advice. I have a 1997 12V 2WD automatic. When it was bone stock it got between 18-20 highway and 17 mpg consistantly in the city. I have straight piped it, installed a AEM cold air intake, and a AFE bladerunner intake manifold. (Also the transmission was rebuildt right before i did these mods). Now im getting between 21-22 mpg highway and 18-19 in the city. What are somemore things that i can do to help get even more mileage out of my 12V??? Thanks
haha im not trying to complain about it at all, its just that i hear and see on forums about 24V cummins getting close to the mid 20's mpg, and i really want to know how you can do that out of a 12V being that I cant simply put in a chip or tuner to increase the mileage
A bunch of little things will add up to help a lot. This list is not specific to our CTD 12Vs but driving differently is worth about 30% difference in economy
Probably most of the "low hanging fruit" is in the aerodynamics of these trucks. Let's face it, we displace a lot of air as we drive. A slanted bedcover (from top back of cab to top of tailgate) is something I definitely plan to do. An "airdam" (some kind of wind barrier that goes down closer to the ground from the bumper) is something else that I will be doing.
Also, make sure you have your drivetrain as slippery as possible. Get the rear end properly lubed. Repack the front bearings and leave them just a hair looser than you might (not loose, but on the loose side of the proper tightness) and be sure your brakes are not dragging at all, adjust them accordingly. Also make sure the alignment is set to as little toe-in as you dare (stock is 0.25 degrees)
another biggy alot of people leave out is your tires man..not necessarily the size but the tread...you need something with very little friction. and keep your boost down....you will basically take all the fun out of your truck by saving mileage but sometimes it's what you got to do.
i seem to be getting around 16-18 mixed normally with 4x4 auto single cab with 265 muds on it..but this last tank is going to be terrible, alloooottt of in town driving since getting laid off...not quite 400 miles in 3/4's of a tank haha..guess that figures out to roughly 14 or so. i think when i put some AT's on it and maybe actually get a real intake i might be able to bump it up a little. plus i think one of brakes is sticking a little somewhere
another biggy alot of people leave out is your tires man..not necessarily the size but the tread...you need something with very little friction. and keep your boost down....you will basically take all the fun out of your truck by saving mileage but sometimes it's what you got to do.
i seem to be getting around 16-18 mixed normally with 4x4 auto single cab with 265 muds on it..but this last tank is going to be terrible, alloooottt of in town driving since getting laid off...not quite 400 miles in 3/4's of a tank haha..guess that figures out to roughly 14 or so. i think when i put some AT's on it and maybe actually get a real intake i might be able to bump it up a little. plus i think one of brakes is sticking a little somewhere
bump your timing, do not know where your at, but if your somewhere cold enough to be running winter fuel, wait till you get back onto #2, should see an increase.
Thanks for the suggestions. As far as my tires im running factory size 10 ply Falken Landair tires, and im running them at 80 psi. (Bumping up the pressure helped a little). My driving habits arent really that bad. I usually in town dont go over 1500 rpm when accelerating unless i need to, and on the highway i usually go 65-70 mph. Are there any other things that i can do to the motor itself to gain a little better mileage? and as far as bumping the timing on my pump, how do you do that?
Upping the thermostat to a hotter one might net you some gains. If you keep a CLOSE eye on the temp gauge, try taking off the fan from the fan pulley.
I KNOW, I KNOW, you probably think that is sooo dangerous, but not running a fan is not that dangerous. Especially on a diesel, which only makes lots of heat when it is under some load (not to say it doesn't heat at dead idle, cause it does, just not a lot)
And unless you get stuck on the highway when they completely shut it down, you are probably going to be moving enough to cool it. Besides, if you were in completely stopped traffic, what are you doing idling your engine if you are trying for better MPGs?
Also, not sure if someone else mentioned it, but upping the pop-off pressure of your injectors should get your engine running more efficiently from better atomization (but if an injector guru steps in to correct me, I will stand (well, sit at my computer) corrected)
As I'm sure you have noticed, most of these cost money. That would be why people on this forum have adopted the "pay to continue playing" saying. However, some of the non-engine mods can be cheap/free. Plastic for aerodynamic mods can be as cheap as free from picking up coroplast election signs from the side of the road and then paint makes it look less conspicuous.
As far as the timing goes, how do you adjust the timing, and will it have any negative effects based on the mods that i have on the truck? (sorry for all these extra questions, im a real newbie at working on diesels). Thanks for the other suggestions too!!! They are all much appreciated!!! Being in college with a diesel pickup isnt easy, but every bit of mpg gain helps a ton!!! My parents want me to get a small car, but this cummins has been nothing but a true blessing to me!!! 239K on the odometer and it has never been to the shop except having the trans rebuilt. Anyways if someone could enlighten me on how to adjust the pump timing i would be much obliged! Thanks everyone!
I used my 12valve for a 210 mile round trip to work. I started hand calculating it during the week and was averaging 18-20 mpg and the highway. This is driving 65-70 most of the time. The more I drive it the more I love it :thumbsup:
I just did a 1200 mile trip,1/2 on 4 lane at 75mph,1/2 2 lane at 60,a little on 2 track & most on snow covered roads & 1/2 at night. I averaged 23 1/2mpg. It's a '95 4x4 2500 w/265x75x16 BFG tires. I love this truck! It will haul or tow anything.go anywhere & get's almost the same mileage of a 4cyl 2wd ranger I had.I want to do power mods but only that work over 2000rpms so I don't mess up my mileage. I can go 700 miles & still have a reserve. Did I say I love this truck?:rof
i got a 1996 2500 ext cab long box 4x4 with a 12 valve and a 5spd with 4:10 gears installed boost and pyro guages and a redneck cold air intake i get between 20 -25 mpg depending on my load and how i drive it(105km average)
i got a 1996 2500 ext cab long box 4x4 with a 12 valve and a 5spd with 4:10 gears installed boost and pyro guages and a redneck cold air intake i get between 20 -25 mpg depending on my load and how i drive it(105km average)
I have never made 20. I get 19 but that is it. On the other hand I got almost 15 with the 5th wheel trailer in my pics on the last easy trip.
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