How big is that thing? I got the fuel light on last night on my way to my gf about 24 miles away. Forgot to fill up on the way home (another 24 miles). We had also driven to Starbucks while I was down there about another 10 miles. It was late and I drove around a bit when I got back to find an open station with diesel (the two I go to were closed due to the time) so add another 10 miles. So I went home. Filled up this morning and put in just a little over 30 gallons. When that gas light goes on, how many gallons am I supposed to have left?

 

35 gallons

 

When the light comes on I think you have about 10 gallons left in the tank. So, to use a conservative est. of 16 mpg you could go another 100++ miles easy. I've gone 60 mile after the needle was on the "E" mark... Same deal as you, late at night, no diesel in sight.

 

Ok, thats what I thought. 35 gallons. I guess a 10 gallon warning is a good thing if your hauling 16000 lbs and getting 10 mpg or less.

The worst mpg I have seen is 17.58 out of a tank of diesel so I use 17 as my judge for how far I can go.

 

Hey screamin, do you have the 12 or 24 valve ctd, and what is your final drive ratio? 4.10 or 3.73:1

 

Got the 24 valve. And the final drive is 3.54 (at least thats what I remember from under the hood). But I wake up and remember my name and its a great thing for me. Thing is, I am not the first owner so it could be the 4.10.

I can tell you 1st gear doesnt even see 9 mph before 2K rpm and 5th at 2K rpm reads 65-66 mph with stock tires.

 

Sounds like 4.10s.

 

The excess fuel pumped forward by the system also is used to cool the Injection Pump before being retuned to the tank.
This is another good reason not to let the fuel level drop 'til yer runnin' on fumes.
The less fuel in the tank, the warmer it will be when it's cycled forward again.

 

How, as a second owner do you tell by lookin under the back end?

As soon as I got the truck I put the tires back to stock size BFGs, the guy who put them on said that it looked like I had a 3500 rear end. Not quite certain what he ment by that, but I figure a bigger axle right?

 

I didnt mean to, usually I hit the gas station as soon as it pings me for fuel low.

 

Look inside the glovebox.
Mine has a sticker on the inside of the G.B. door.
says "Axle Ratio - 4.10"

When I'm close to home, I usually try to hit a fuel station when mine gets to 1/2 tank.
On the road - down to 1/4 tank.

 

LOL, mine says 3.somthing. Its at the shop at the moment so I cant check.

 

Because you have a 2500 w/5 spd, you have a D80 hybrid axle that uses a D70 style ring and pinion but has a D80 carrier.....Auto's have the somewhat smaller D70.....if you have factory sized 245/75's, 2000 rpm @ 65 mph is about right for 3.54's and a 5 spd.......you should doing about 67-68 mph @ 2000 rpm with 265/75's and the 5 spd.......OD on the 5 spd is not quite as high a ratio as the OD on the auto.

The fuel light on my 98.5 also comes on with about 10 gallons left in it....