azjeff

I had to make a quick unexpected trip to Fort Worth and back from Phoenix last weekend. I didn't do a thing but get in the truck and go, and made the trip empty, just me and no cargo. I always wondered what kind of fuel mileage to expect on a trip like that since I can rely on 18-18.5 on my normal around town driving.
Going I went through Albequerque/Amarillo and averaged 21 mpg at 80-85 mph - 1,080 miles. Return was through Midland/ El Paso, and again 75-85 mph and averaged just over 22 mpg for the 1,090 miles - flat land trip. It was great, get tired & park and sleep on the rear seat until ready to go. Fuel was much less expensive than in Arizona. Typical cost was $1.51 - $1.58 in NM & TX, in Phx it is $1.90 to $2.10 - go figure. Truck is pretty much a stock 2000 with 4" exhaust and Stanadyne addititve and now has 199,000 miles.

J BODY

I take it that the US gear splitter allows you to keep your rpms down a bit at the speeds you described. When I first got my 01 it had 4.10's and at 75mph I would be turning 2300-2400 rpm and the fuel mileage was 14-15. After changing to 3.55's the rpms dropped about 400 so the mileage at 75 now is 18-19. At 80-85 the rpms creep up on me again and the mileage suffers. Wait till you take a road trip through some mountain areas. Nothing like driving a truck that doesn't even think about shifting down or coming out of lockup. You get to a grade and hear a little more turbo whine and they just keep pulling. Life it grand when driving a CTD!

azjeff

No, the splitter is in the '95. The 2000 is just a plain CTD quad cab w/ 3.55's. I pull an equipment trailer sometimes that's kind of heavy as the truck and loaded trailer is 17K. It is not bad going up the hills, since I can still pass some semi's. At 80 empty I'm showing about 2150 r's. It does have undersized 245's on it to kind of makeup for the 3.55's. Returning from Flagstaff 2 weeks ago (7,500'), I filled the truck and zeroed the odo, and got an amazing 26 back into Phx which is about 150 miles. I drove around town some over the weekend and drove back to Flag on Monday and then back down the same day on the same tank of fuel. Going up, it's not that good, but I still averaged by the fuel used about 22.5 mpg in the 575 miles put on that tank. I usually fill at just before the light comes on in normal driving around Phx and take 26-27 gal for approx 475-500 miles. Also, a/c on or off doesn't seem to make any difference.

It's pretty incredible. I'm thinking of opening up the inlet air to see if I can stay in the throttle while pulling & keeping the egt's below 1200. Can't do that now, it approaches 1400 rapidly if I'm heavy & I have to back off to keep it lower. I'll be working on that soon. Jeff

J BODY

No, the splitter is in the '95.

Guess it helps if I would read the sig a little closer. Thats some great mileage, of course dropping from 6K elevation down to 1300 helps the numbers quite a bit on that 26 number!

magnum

azjeff,

What you failed to mention on your trip from Flagstaff to PHX in your incredible fuel mileage is that ITS ALL DOWN HILL!!

Seriously though===great numbers, I'm still in the 18-19 avg year around empty mode.

CoastalDav

My 96 would get 21-22 on the hwy with the 12 valve. My 2000
usually stays around 18 at 70mph. It a dually and I have a little more weight and rolling friction.

Your right though, they love to run around 85. Thats about the same rpm as a 4:10 at 65 or 70.

Have fun with it.

Dave