It's getting to be about that time....

[bbaCJ8]

I guess we’ll see. It’ll still be better than the 12mpg I’m averaging now but 20 would definitely be nice. Hopefully the Smarty will help when I’m not driving like a pissed off teenager.

[agoldxj]

that's true my truck is on stock programming so you may do better.

[bbaCJ8]

This one is stock programming right now too but I don't imagine I'll be able to hold off too long on a Smarty. Hell, my best friend has a Smarty on his truck too, so maybe we'll even pull it off his and put it on mine for the trip since it's not VIN locked.

[awheelterd]

haha, if you drive your truck home with the smarty, then go back to stock tune, you'll end up buying one within a month

[mcamish01]

Originally Posted by bbaCJ8

A buddy of mine has a stock 05 CTD on 33s and claims he got just shy of 23mpg at 85mph driving

I got no problem calling BS on this. My stock '01, on 33s, will get a max of around 21 mpg (but i'm on 4.10s) at around 55-60 mph. At 70-75 I'm back to around 18mpg. I don't doubt that he can push 23mpg, especially if he's got 3.73s, but it ain't happening at 85 mph end of story.

As for the new 6.7s, I think they've gotten a bad rap as far as mpg figures go, mostly from guys who haven't broken them in fully yet. Obviously, they'll never touch a 2nd or even a 5.9 3rd gen for fuel economy, but I know several guys getting 17 and even 18 mpg out of them after 30k, which is pretty spectacular for '07+ emmisions trucks from any manufacturer.

[bbaCJ8]

Originally Posted by awheelterd

haha, if you drive your truck home with the smarty, then go back to stock tune, you'll end up buying one within a month

I know, that's the problem. I built his suspension and stuff for him so I've driven the truck a good bit. Even with no tune and 40s on 3.73s it still felt very powerful and drove just fine....amazing how 650 lb-ft of torque will make up for some big asss tires! I've also driven it with a TST tuner, Smarty, and TST and Smarty stacked and the tuners were definitely more fun than stock. Hell, the Smarty is worth it just to roll some coal!! But if that were all I cared about I'd just put a smoke switch in it.

[FUBAR]

I'd get the Raptor and swap in a PSD.

[OkLaHoMaTJ]

Originally Posted by mcamish01

As for the new 6.7s, I think they've gotten a bad rap as far as mpg figures go, mostly from guys who haven't broken them in fully yet. Obviously, they'll never touch a 2nd or even a 5.9 3rd gen for fuel economy, but I know several guys getting 17 and even 18 mpg out of them after 30k, which is pretty spectacular for '07+ emmisions trucks from any manufacturer.

This is with the emissions untouched or deleted correct? I have seen this too. Mostly on the higher mileage 6.7L's.

[agoldxj]

Originally Posted by bbaCJ8

I know, that's the problem. I built his suspension and stuff for him so I've driven the truck a good bit. Even with no tune and 40s on 3.73s it still felt very powerful and drove just fine....amazing how 650 lb-ft of torque will make up for some big asss tires! I've also driven it with a TST tuner, Smarty, and TST and Smarty stacked and the tuners were definitely more fun than stock. Hell, the Smarty is worth it just to roll some coal!! But if that were all I cared about I'd just put a smoke switch in it.

better keep it turned down or bye bye 48retarded. i don't plan on adding much hp to mine but this summer i am going to be a doing a hd transmission. mines fine but ive ridden in trucks with built trans and it's night and day.

[bbaCJ8]

Originally Posted by agoldxj

better keep it turned down or bye bye 48retarded. i don't plan on adding much hp to mine but this summer i am going to be a doing a hd transmission. mines fine but ive ridden in trucks with built trans and it's night and day.

Yep, I'll just get a Smarty Jr and leave it on SW2. Probably put in an upgraded converter and valvebody for the time being, then somewhere down the road put in a built trans. I'm in the market for a house later this year so buying an almost $30k truck and a $6k trans would definitely be pushing it.

Everybody on CumminsForum has so many horror stories about the 48RE it had me all worried and nervous. They say to never put it over SW3 on a stock trans and all that stuff. Well my best friend runs around everyday on SW7 on 40" tires and beats the living crap out of it with a bone stock 48RE. He even had it on SW7 and stacked with the TST for a while. He blows through the converter on all his boosted launches, heats it up at the dunes, etc. Basically does everything you're not supposed to do to a transmission, and it just takes it like a champ. I don't plan to abuse mine anywhere near like that so hopefully mine holds up well.

[OkLaHoMaTJ]

Agreed on the CumminsForum horror stories. That website almost made me turn back to the 7.3L or the 6.6L. However, I do believe that the Cummins is a better truck. I've heard back and forth opinions on the 48re and in stock form I think it is a great transmission.

I read stories like this all day on that site....

"My 48re took a dump and I don't know why"...then later in the post you read "well it does have a tuner/chip, lift, 37's and I was pulling 20k pounds with it tuned way up."

[agoldxj]

i agree the 48re is a great unit for stock power and can be easily upgraded to last a long time with stock tuning. but yeah most of the stories are like oklahomatj said..

[mcamish01]

Originally Posted by OkLaHoMaTJ

This is with the emissions untouched or deleted correct? I have seen this too. Mostly on the higher mileage 6.7L's.

I believe the fella who was touching 18 mpg had the regen equipment deleted, but I know a couple of guys pulling 17s out of 6.7s with the emissions still intact.

Have heard great things about the new 68re too, not to say that the 48re's are trash. Like its been said, most of the 47/48re failures stem from boosting the hell out of the motors and towing pretty heavy loads, but if I HAD to have an auto i'd hold out for the 68re, or see what it'd take to swap one into an older 5.9

[bbaCJ8]

Yep the 68RE is pretty badasss but the 48RE is no slouch either, like you guys said above. I spent very limited time in my buddy's 07.5 CTD with the 6.7L and 68RE. It seemed very nice, quiet, smooth, etc.....and I was quite hungover at the time so I noticed those things. Then again I'm used to my other friend's very modded 5.9L on 40s so my idea of smooth and quiet is a little "off".

As long as this truck can take what I'll be throwing at it I won't complain. Based on what I've seen I'm not worried.

[OkLaHoMaTJ]

I agree bba....whatever year CTD I buy it'll be very tame. Mainly for longevity purposes. I have no desire to "roll coal" or race my truck. I want it to be efficient, get good mpg's, and tow my TJ anywhere I desire.

[bbaCJ8]

Originally Posted by OkLaHoMaTJ

I agree bba....whatever year CTD I buy it'll be very tame. Mainly for longevity purposes. I have no desire to "roll coal" or race my truck. I want it to be efficient, get good mpg's, and tow my TJ anywhere I desire.

Yup I plan to keep it pretty tame and DD it for a LONG time too. I've got other toys for the real fun(supercharged Scrambler will eventually be done, and I may turn the current truck into a BDMT in the meantime), but I don't doubt that the CTD will eventually get some power adders and a built trans for fun and reliability.

[GPSflyer]

Cool truck man! The 48RE is not a bad trans, and with what I've seen you build on here, you'll have no trouble upgrading the trans yourself.

Only thing I do recommend, is a good additional fuel filter. Common Rail injectors don't like dirty fuel, so a 2 micron filter is good insurance.

Have fun with it!

[bbaCJ8]

Originally Posted by GPSflyer

Cool truck man! The 48RE is not a bad trans, and with what I've seen you build on here, you'll have no trouble upgrading the trans yourself.

Only thing I do recommend, is a good additional fuel filter. Common Rail injectors don't like dirty fuel, so a 2 micron filter is good insurance.

Have fun with it!

I've only been inside an auto(TH400) once and I hated it, swore I'd never do it again. When the time comes I'll at least pick up a book or two on rebuilding a 48RE and see if it'd be worth the trouble of doing it myself. In the near future I'll probably upgrade the torque converter and valve body to improve things on a budget, but eventually I'm sure it'll be time for upgrading the internals, shafts, flexplate, etc.

Something like a FASS or Airdog would include the additional filter, right? That'll be near the top of the lift once mods start trickling in. Is there a better(ie cheaper) way to do it in the meantime? I'm very new to diesels so any tips are more than welcome!

[GPSflyer]

Originally Posted by bbaCJ8

I've only been inside an auto(TH400) once and I hated it, swore I'd never do it again. When the time comes I'll at least pick up a book or two on rebuilding a 48RE and see if it'd be worth the trouble of doing it myself. In the near future I'll probably upgrade the torque converter and valve body to improve things on a budget, but eventually I'm sure it'll be time for upgrading the internals, shafts, flexplate, etc.

Something like a FASS or Airdog would include the additional filter, right? That'll be near the top of the lift once mods start trickling in. Is there a better(ie cheaper) way to do it in the meantime? I'm very new to diesels so any tips are more than welcome!

Yes, a fass/airdog both come with nice filters. On my CR superduty, I already had a nice aftermarket lift pump, so I bought a Racor stand alone unit. Its a 2 micron, with internal heater and primer pump. I get all of my filter supplies from A&L Systems in Redford, they're just off of telegraph & I96. They supplied me with all of my oil bypass systems too. If you go down there, they will actually show you all of the different types of filters, and how they work. After seeing the oil filter tests, I'll never run a cheap filter again!

Whatever you choose, look for a minimum of 2 micron filtration for your fuel.