Cummins Diesel Forum banner

6.7 or 5.9

2K views 22 replies 20 participants last post by  mulisha 
#1 ·
should I get another 5.9 or should I get the new 6.7?
 
#4 ·
what? you two cant be serious. My 2003 (250hp?) feels way stronger and gets 8 more miles to the gallon. Plus it sounds and smells like a real diesel. I havent really pulled anything with my 6.7 so i cant say there but around town and hwy id take the 5.9
 
#5 ·
Yes, if you mod the 6.7 then get in a 5.9 you will like the 6.7 more.:woot:
 
#6 ·
You're obviously going to get biased opinions. If I were you I'd find a dealer that'd let you bring a 6.7 home for a few days. 6.7 are stronger motors but modding them is risky when it comes to keeping you warranty. Not much to say, just drive one and see for yourself.
 
#15 ·
If you have a modded 5.9 and test drive a stock 6.7 you will be dissapointed in power and millage of course, i was, now that my 6.7 is modded, there is only one thing to say..... anyone want to buy my 5.9??
 
#7 ·
I gotta say what others have said. I like the 6.7 over the 5.9s i have had. Yes its a little more work to mod, but well worth it.
 
#10 ·
I'm a diehard 5.9 fan also. The thing that sold me was the 68rfe. I love the way the thing shifts, it seems strong as an alison, and you don't have that huge drop that the 48re had going into OD. The motor run's great, I've ridden in some 5.9's that make more power, but none of them are nearly as drivable. I've done some mods, and yes their harder, more riskey but more rewarding:woot: The 6.7 get's my vote. Don't forget the E-brake, it's awsome
 
#11 ·
I've had eight 5.9's and now a 6.7 and I wouldn't go back. The 6.7 is as fast bone stock as a 5.9 with a 75HP box and straight pipe.
I ran a 15.21 on my 08 when it only had 600 miles on it and the best time I ever got out of my 05 with an Edge EZ, AFE StageII with PG7 and no muffler or cat was a 15.15. Same track, same basic weather.
And if you are pulling a big trailer you cannot even compare the two.
 
#12 ·
Sometimes I wish I'd gotten the 68re, sometimes I'm glad I got the G56

even with all the problems I've had with mine, I think they finally got them worked out and it's turning out to be a really nice truck. Just wish it didn't have the EGR or DPF on it, but their time is limited now :D
 
#13 ·
Yours is only 2 years old, why do you want a new truck already? If you don't like the 5.9 you have, does that answer your own question? The 6.7 has lots of smooth, quiet power, and sucks lots of fuel compared to the 5.9. If you don't mind losing your warranty you can take off the pollution crap and make up some of the lost mpgs
 
#20 ·
From what i've been reading in the 6.7 threads, it seems that they're getting anywhere between 14-18, occasionally a strayer at 19. In the 5.9's, i've heard anywhere between 16-22...it all just depends on what you're going to be doing with it.

I have the 5.9 and as a daily driver, i average about 21 between city and highway driving. Strickly highway and long runs, i've done a bit better with a 22 hand calc, but when I tow the 16' dump trailer, i average between 16-18, depending on if its empty or loaded with crap and I try to drive without putting my foot through the floor.

As far as this thread, the 5.9 is easy to mod, the prices are dropping on the used ones and it gets the job done...no b.s. The 6.7, especially in the early transition (07.5's), many have had mileage issues, CEL's and whatnot and i've read that the 08's have corrected these issues.

So in short, if you're looking for mileage - 5.9
If you're looking for more power and quicker towing, then 6.7

Can't have both, unfortunately. Although, there's some impressive 5.9's mod'ed to the ying yang and they're pushing over 500hp and 1000+ tq.

Hmmm...less expensive 5.9 with a ton of mods to outrun the 6.7? Guess that's a choice you'd have to make too. But I couldn't tell you what the end result would be on mileage.

:ah:
 
#22 ·
The 6.7's drive a lot smoother. Like a SUV. The 5.9 is rougher riding truck.
 
#23 ·
opinions will be biased,but look at this, the 5.9 motor is on the top 10 list of best engines ever made. that includes every motor built, from airplanes, to tractors, to trucks, ect. the 6.7 just has too much junk on it. and is still having problems with turbo's,DPF, ect. i personally know 2 people including myself who owned the 6.7,and now have 5.9's. easy decision.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top