3rd Gen Engine and Drivetrain -> 2003-2007 5.9 liter Engine and drivetrain discussion only. PLEASE, NO HIGH PERFORMANCE DISCUSSION!

5.9 or 6.7

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Old 08-19-2010 | 07:03 PM
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5.9 or 6.7

Which is better a 5.9 or 6.7 for performance, reliability and milage?
Old 08-19-2010 | 07:36 PM
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From: Arizona - The Photo Radar Rip-off State
Performance - 6.7

Reliability and mileage - 5.9

If you do the deletes the 6.7 would be awesome, but no warranty and you have to worry about the EPA Gestapo. I've owned both, and I sold the 6.7 and kept my 5.9. It does everything I want it to do, and I pull a lot of heavy loads.
Old 08-19-2010 | 07:46 PM
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Same here I just sold my new 6.7 I had it turned up Smarty all the deletes 5" turbo back and I hated that truck! I have a 05 And LOVE it You could not give me a NEW 6.7 Big Joke just my 2cents
Old 08-19-2010 | 08:01 PM
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5.9L for the WIN
Old 08-19-2010 | 08:35 PM
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I had a 2000 5.9 and moved up to the 6.7. Once the engine can breath, its a whole new animal. I will have to vote for the 6.7. Its quiet and smooth, the 6 speed auto with engine brake is amazing.
Old 08-19-2010 | 09:34 PM
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5.9
Old 08-19-2010 | 10:45 PM
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everyone that i know that hauls with the 6.7.. has had there exhuast brake stick on them... and its expensive fix because some of them had it stick and melt the #1 piston..
another wierd issue is they have a 3rd and 4th injection per cycle for emissions and compression knock control.... and because of this the injectors see alot more use compared to the 5.9
Old 08-20-2010 | 10:48 AM
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From: Home: Kaplan, LA - Pipelining In: Pecos, Tx
Originally Posted by ramble bee
Same here I just sold my new 6.7 I had it turned up Smarty all the deletes 5" turbo back and I hated that truck! I have a 05 And LOVE it You could not give me a NEW 6.7 Big Joke just my 2cents
What did you hate about it so much?
Old 08-20-2010 | 02:56 PM
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I could not get use to the Trans and the Motor. Stock I could see EGTs through the roof when in Regen and it was in all the time! Then I did all the deletes and that helped the EGTs but the truck ran Strange. I had the Smarty on it everything was ok But when you got on it the turbo acted real strange as well. I got spanked so my times in it I hated to even bring it out!
I am a 5.9 Guy and thats my thing, not the 6.7 turds
Old 08-20-2010 | 02:57 PM
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From: Home: Kaplan, LA - Pipelining In: Pecos, Tx
Well, I can understand you preferring the 5.9 but that doesnt make the 6.7 a turd....

To each his own.
Old 08-20-2010 | 03:48 PM
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I've been nothing but impressed with my 6.7. Even more so since doing the deletes.

Hands down I'll take a 6.7 over any gen 5.9
Old 08-20-2010 | 05:33 PM
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ummm...wonder what the answers would be over in the 2007 and up forum...
Old 08-20-2010 | 07:03 PM
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there good motors.. just the exhaust brake tends to stick up and melt piston #1 just fyi... i have over 30 friends that have melted piston #1 while towing and using the exhaust brake...
Old 08-21-2010 | 02:20 AM
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5.9
Old 08-21-2010 | 01:24 PM
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I loved my 6.7 with the EB and auto. However i just got me a 5.9 with the 6spd and seem to like it a little more so far. Mileage is better on the 5.9 but i also had a level kit which hurts the mileage on the 6.7. I NEVER had my 6.7 do a regen and the power of it was great. So i can not say anything bad about it.



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