what is the best mpg's that y'all are getting with the 6.9 diesel thanks

 

I've got the 7.3 in my 88, but I get a fairly steady 16-18 with mostly highway driving.

Also worth mentioning I have the C6 tranny, so it's only a three speed. I would imagine you could get 20ish with a 5 speed and running some Stanadyne or some other such diesel additive.

 

I too have a 88 7.3 IDI, running Atf ( 1 qt per 50 Gal. per fill ) city 17.6 ave, frewway 20... steady I have a 4 spd, 3.55's and 315/75/16's ... running the Cooper AT/3's ... love'em , handles nice easy snow driving and handles awesome in dry too .... just about done with the top end rebuild ... check it out in my post ... 88 ford build ..

 

When my 90 7.3 idi NA was running (2 weeks ago) I got about 19 city and 21ish highway, 5 speed manual

 

You guys are getting way better MPG than my 2008 F-250 6.4
STOCK I was getting 11 to 13
DELETES i'm getting 13.8 to 14.8
my driving is city only

 

I highlighted your problem with poor mpg

 

LOL... Right ..

.......

 

I'm not one to talk, my current dd gives me about 9 mpg, and I drive 97 miles daily monday - friday

 

460 ?

 

you would think, but it's a 351