I'm a newby to this page, and I have been reading the forum for two days looking for good info and I am about as confused as I can be.

Here's what I have. 1994 E-350 extended. 4.9 inline six, I think I have a C-6, though there is conflicting info on this page. P-R-N-D-2-1. I have tuned this engine completely and am getting all clear codes. I am using sythetic oil. I don't know what gears I have but I will find out.

This is what I do, I am a courier and I run 300 miles a day hauling about 1/2 to 3/4 tons of library books. Mostly flat with a few hills, and the majority of the time 60-65 mph.

I am getting about 14 mpg every day. Which seems about normal from what I have read in the forums. So I am spending about $200. a week for fuel. Under these conditions any increase would amount to a quite a bit of money in a years time. The six seems to be straining most of the time on acceleration and up hill and is at pretty high rpms when cruising.

As best as I can tell, swapping engines would not help a lot and would not be as bullet proof as the 300 is but adding overdrive would seem to be helpful (possible AOD swap?). I don't know about the gears do I need to go a bigger number or smaller?

I know this is pretty sketchy but what advice does anyone have?

 

I'd be happy with 14mpg if I was you. That sounds rough, but you're probably never going to get better than 16mpg even with a OD tranny.

 

I will only get 14-15 in my half ton if it is all highway driving. The price it would cost you to switch over to AOD tranny, is probably not worth it.

Just a little note, my truck gets the best gas mileage when I try to run it at 1800-2000 rpm's, however, it is guttless at that. Hopefully this will help.

 

Replace the air filter more often and see what happens you will bw amazed.

 

1234567890

 

My truck the other day got a recorded 17.8 mpg with my M5OD tranny.

My recommendation to you? Drive 55 mph instead of 65. Your engine wont' have trouble at that speed, and plus - for every 5 miles over 55 you go you generally lose one mile per gallon of gas. I understand you're traveling 300 miles a day...but if you want better economy.

The 300's torque starts to really come on about 1750 and continues through 3000 - peak is like 2200 rpm's. HP peak is at 3400 rpm's.

Anybody know the redline on 300's?

 

Slowing down will help, but I have been playing with my truck to see what I can get for MPG as well for highway.

I would change out the fan to an electric. Anything over 30 MPH and you don't really need to run the fan as airspeed pushes enough air through the radiator. I would of course put it in with a thermostat controlled electric for safety anyway. (you do have to drive slower sometimes )

But on the highway, you are dragging the stock fan (even with a fan clutch) when it is not needed.

You can also change your rear end lube to synthetic. I made both of these changes (Along with a more open exhaust when it needed replaced anyway) and got 3-4 additional mpg on the highway. That would save you about $30 per week. The fan kits are around $100-120 so you would pay for it in about a month.....

Just a thought.

Jim

 

Thanks for all the input, it gives me much to consider. Gas is going down a little so I think I will hold off a while on the major changes but I will do the simple things.