Does anyone have a good handle on any MPG difference btwn these two engines?

 

Probably too darn many variables to get a good handle on the difference;summer vs. winter, highway vs. city, bigger tires, individual driving style......

I have an '06 F250 6.0, 3.73 axle and Manual trans. At 60-65 mph on the highway, in the summer, with 265/70x17 tires at 65 psi, I can sometimes get just over 20, usually just under 20. At 70-75 mph, it's closer to 18. In the winter, with 285/70x17 tires at 55 psi, you can knock off 2 to 2-1/2 mpg.

Around town, it's 17 summer & 15 winter, but I'm a pretty smooth, conservative driver.... can't see smokin' the tires to impress people at $200 a tire.

Towing a 33' Travel Trailer at 65 mph in the summer, it's between 13 and 14.

 

Like wwb said there are alot of variables. When I drive my pickup 65 it makes 22. I rarely drive that slow, but the few times I have and checked the mileage that is what it did. 75 to 80 highway only ranges from 19 to 20 depending on wind and terrain. Most of the time mixed driving gets 17 to 18 depending on how easy I am on the throttle. Towing our 34' 5er 12 to 13.

Basically if you keep your speeds low on the interstate you can make some really good mileage.

BTW I dont keep track of mileage in the winter, blended fuel is alway worse mileage.

 

with my 97 7.3 with the mods in my sig i've been getting about 15 with a fuel leak... just fixed that fuel leak on sunday so we'll see what this next tank brings

 

stock 2002 7.3 except for intake and exhaust, I get 16-18 unloaded... pulling my trailer I can still get about 15 or 16 (sometimes better), it only weighs about 6k pounds.

 

Like other people have said mileage numbers aren't going to mean a whole lot to you because people that give you great mileage reports might have different driving scenerios compared to you and you may or may not see the mileage numbers that they gave you. I have seen people put down great mileage numbers for the 6.0 and I haven't come close to those numbers myself. Bottomline, what people tell you isn't going to mean truly anything to you because of too many variables. For instance, what wwb gave for mpg when towing a trailer in the summer I see empty, towing what I see, you don't want to.

 

My '97 F-350 gets 17.25 MPG combined city/highway unloaded. Towing a 24-foot travel travel, she drops to 12 - 13 MPG.

 

Driving habits will give you the biggest difference in MPG's, but generally speaking the 6.0's are a quicker motor with slightly worse mileage. I'm currently running (4) 7.3's and (4) 6.0's at work. Proper driving in the 6.0 can be better than bad driving in the 7.3, but with the same driver in both trucks the 7.3 wins the MPG by a little.

 

You also have to take into account the setups of all those trucks: gearing, DRW or SRW etc. or else it's not going to be a really fair comparision. There are just too many variables, in order to have a fair comparision you would have to have both trucks configured exactly the same and try to drive them both the same way as best you can and travel the same exact route and then you would be able to have a much better estimation of mpg of one motor over the other.

 

Sorry I wasn't clear, but my observations are all on completely stock trucks that are similarly equipped. I have personally driven the different trucks so I'm making my comparisons on both my driving experiences and the MPG average of the trucks after they were put in the fleet.

 

truck is in my sig. with 3.73s towing a 39ft 5er over 11K gets 10 to 11 mpg. at 60 mph.

and empty in town 15 mpg.

 

good enough.

 

normally what I'VE noticed is that the OBS 7.3s get better milage than the superduty 7.3s (less weight to move around) and that the superduty 7.3s get better milage than the 6.0s (less weight and the 6.0 is a smaller/higher revving engine)