How long does it take before the MPGs improve
All Star
Joined: Dec 2008
Posts: 863
Likes: 0
From: East Alabama
Okay, let's get the skinny on the Smarty S67 and your fuel mileage.
The 6.7 will normally get you between 13 - 15 MPG unload the way it sits from the factory. Even after it's "broken in" (at 30K - 35K miles), it's still not going to get much better than that.
The reasons for it are 1 - The DPF, 2 - the EGR, 3 - the 4th injection event, and 4 - the ECM going into active regen mode if it detects too much back pressure at the DPF.
Now, remove the DPF and add a Smarty and you'll see a 2 - 4 MPG improvement. First, you'll no longer have the DPF to clog up and cause the regen function and second, you can mess with the timing which is were you net the biggest gains on a diesel.
THE biggest cause of the crappy mileage is the DPF and the regen function. Get rid of that and you gain both power and mileage.
For it to all work correctly, you want to delete the EGR also. This is the main cause of the problem that some folks experience withe turbo on the 6.7's. Reintroducing spent exhaust gases into the intake is just brilliant (insert sarcasm). Once that is out of the way, you're golden. If you want to really scare yourself, take the intake horn off your truck and look into the manifold.......it'll be black with soot from the damn EGR......and that's suppossed to be filtered air to the engine. Again, brilliant idea.
Once the DPF and EGR are deleted from the 6.7, it's an animal.
Will it void your warranty? Yes.
Is it worth it? That depends on you.
If it was my truck, that junk would be off the truck right after it left the lot.
The 6.7 will normally get you between 13 - 15 MPG unload the way it sits from the factory. Even after it's "broken in" (at 30K - 35K miles), it's still not going to get much better than that.
The reasons for it are 1 - The DPF, 2 - the EGR, 3 - the 4th injection event, and 4 - the ECM going into active regen mode if it detects too much back pressure at the DPF.
Now, remove the DPF and add a Smarty and you'll see a 2 - 4 MPG improvement. First, you'll no longer have the DPF to clog up and cause the regen function and second, you can mess with the timing which is were you net the biggest gains on a diesel.
THE biggest cause of the crappy mileage is the DPF and the regen function. Get rid of that and you gain both power and mileage.
For it to all work correctly, you want to delete the EGR also. This is the main cause of the problem that some folks experience withe turbo on the 6.7's. Reintroducing spent exhaust gases into the intake is just brilliant (insert sarcasm). Once that is out of the way, you're golden. If you want to really scare yourself, take the intake horn off your truck and look into the manifold.......it'll be black with soot from the damn EGR......and that's suppossed to be filtered air to the engine. Again, brilliant idea.
Once the DPF and EGR are deleted from the 6.7, it's an animal.
Will it void your warranty? Yes.
Is it worth it? That depends on you.
If it was my truck, that junk would be off the truck right after it left the lot.
Thread Starter
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Rookie
Joined: May 2010
Posts: 95
Likes: 0
I bought the truck at Piedmont Dodge in Anderson, which is close to my house.
I should be in NY right now but the plan was to take a long trip in my camper after I finished in NY but the fridge in my camper didn't work right the day I got it. I spent a lot of time trying to fix it and gave up and bought a new one from a different manufacturer.
I am going to wait and think before I do any mods to the engine. I just bought the truck with and extended warrantee so I would not only loose the manufactures warrantee, I would also loose the add on warrantee.
I should be in NY right now but the plan was to take a long trip in my camper after I finished in NY but the fridge in my camper didn't work right the day I got it. I spent a lot of time trying to fix it and gave up and bought a new one from a different manufacturer.
I am going to wait and think before I do any mods to the engine. I just bought the truck with and extended warrantee so I would not only loose the manufactures warrantee, I would also loose the add on warrantee.