How to increase Fuel mileage 1998 Blue Bird Mini. 6.5l Detroit Diesel

[Lostwon]

Hello friends.

I have a 1998 Chevy/GMC Blue Bird Mini that has: 6.5L Detroit Diesel. This engine uses Indirect injection as its fuel delivery to the pistions. This link pic/info https://en.wikipedia.org/wiki/Blue_Bird_Mini_Bird.

I had the transmission replaced when I get it. Besides that Everything in it is stock.

I seem to be averaging 9.5 to 10 MPG on average.

I cant find what fuel economy it should be getting anywhere and I have been searching quite a bit.

I've been spending lots of time reading this forum and have seen a few references to changing the rear differential gearing (or something in the back end) and would like to know what ratio my has now and what I could change it to to increase MPG.

Beyond that, any little tips of mods that could be done to squeeze even 1 MPG overall outa this beast.

Would stopping the flow of the water to the various heater cores while driving in anyway increase the MPG?

I travel constantly so every MPG I save is very worth it to me.

My RPMs max around 3700 but I generally run around 2150.
My automatic transmission wont change into OverDrive until 55 mph around 3200 RPMs. I idle at 600 while resting and 700 while coasting a hill in neutral.

Thanks Friends!

[zelseman]

Originally Posted by Lostwon

Hello friends.

I have a 1998 Chevy/GMC Blue Bird Mini that has: 6.5L Detroit Diesel. This engine uses Indirect injection as its fuel delivery to the pistions. This link pic/info https://en.wikipedia.org/wiki/Blue_Bird_Mini_Bird.

I had the transmission replaced when I get it. Besides that Everything in it is stock.

I seem to be averaging 9.5 to 10 MPG on average.

I cant find what fuel economy it should be getting anywhere and I have been searching quite a bit.

I've been spending lots of time reading this forum and have seen a few references to changing the rear differential gearing (or something in the back end) and would like to know what ratio my has now and what I could change it to to increase MPG.

Beyond that, any little tips of mods that could be done to squeeze even 1 MPG overall outa this beast.

Would stopping the flow of the water to the various heater cores while driving in anyway increase the MPG?

I travel constantly so every MPG I save is very worth it to me.

My RPMs max around 3700 but I generally run around 2150.
My automatic transmission wont change into OverDrive until 55 mph around 3200 RPMs. I idle at 600 while resting and 700 while coasting a hill in neutral.

Thanks Friends!

It seems to vary so much from vehicle to vehicle. Some Chevy trucks with the 6.5L get mid to upper teens, but they aren't carrying around a big huge heavy box on the back either. Keeping the speed/rpms low and staying out of overdrive will help. Good luck, I love my 6.5L so far!