im new to the diesel world if the following isnt obvious. my 06 gets 15.5mpg on a good day. is this normal? can i do anything to make it better? My old trans am put out 500hp to the rear wheel and still got 20-25mpg. i even drive like miss daisy to eek out a little more economy. im open to suggestions...please help!

 

Fill out your sig, so we know exactly what you're running.

1. Patience if it's new, takes 20k unloaded to break-in and about 5-10k if you tow or load heavy.

2. I'm getting 15.9 city currently with 10k on it, no towing, 1/2 cord of wood is the heaviest I've loaded so far and that was only for 30 miles.

 

You didn't specify what truck you have and how many miles are on it.
15.5 in winter, in a cold climate, doesn't sound too bad.
I find that you loose 2mpg running winterized diesel. Plus the amount of time that it takes the engine to warm up in winter affects the mileage.
I get about 15 in winter and 17 in summer with my 06 MegaCab.

 

Also remember your Trans am probably didn't have 610lbs of torque and weigh over 7000lbs and chances are it was probably a bit more aerodynamic.

And if it's an auto use Tow/Haul when driving faster than 50mph.

And use hand calcs not the overhead, mine says 14.4mpg and hand calc is 15.9mpg.

 

Holy Moly! I'm luck to get 12 in town with 23,000

 

Hotrod, much?

I'm in the SF bay area, I know my traffic must be worse.

45-60min for 23 miles.

 

why? doesn't this lock out the O/D?

 

I have an 06 with less than 2500 miles on it, purchased in early December of 2006. I was getting between 15.5 and 16.1 mpg hand figured with a mixture of Power Service diesel additive and Marvel Mystery Oil.
I recently tried a 50/50 mixture of Howe's Meaner Kleaner and MMO, 16 oz per tank. It jumped to 16.9 mpg, hand calculated on the first tank.
All driving was a mixture of city and highway.
I expect to get between 17 to 19 once the truck is fully broke in!

 

JFYI here, and for future reference, diesels get "FUEL MILEAGE" not "gas mileage"!!!!!

 

And if it's an auto use Tow/Haul when driving faster than 50mph.

Whats the reasoning behind that?

I've been running winter fuel for the last 2 weeks (-30 degrees out) and the other day i drove from home to college and got 22.8 MPG doing 70 so i was pretty excited i have 15500 miles on it now.

 

15-16 city driving is just about right

 

Not on the 06's, it locks up the converter, no slippage loss of MPG.

2006 has O/D, T/H with O/D, and O/D off.


See above comment.

 

using tow/haul on the 06 does that - what about 04s? All it does on mine is raise the rpms.

 

04 doesn't have that feature, sorry.

 

thanks. I had read on here other posts about multiple push capability on the tow/haul button but every time I did that, all it did was climb rpms, thanks for confirming for me!