Gas mil. on 1999 454

[ROD1969]

I found a 1999 GMC 454/auto. crew cab dually short box and was wondering if anyone knows of the gas milage on it.

 

LOOKING AT BUYING ONE OF THE THREE

 

2002 GMC CREW CAB SHORT BOX 8.1L/ALLISON

1999 GMC CREW CAB SHORT BOX DUALLY 454/AUTO

1999 GMC CREW CAB SHORT BOX DUALLY DIESEL/AUTO

[LikeaRock14]

I've got an 00 CC srw w/ the 454 and 4:10's, it averages around 10-11 arround town, 12-13 short trips down the freeway, but I can get around 15 interstate cruising

[whitesnake01]

I've got an 00 CC srw w/ the 454 and 4:10's, it averages around 10-11 arround town, 12-13 short trips down the freeway, but I can get around 15 interstate cruising

I've got about the same experience with my 93 and 3.73s. I get around 9mpg towing a 8,300lbs trailer.

 

For the 99 truck you'd be looking at the 6.5L Turbo Diesel. Not DMAX. Not Allison. They do pretty well. But do not have much power. I think they have around 190HP/385TQ.

[dannyukonxl]

thats weird i thought the 1999 diesels (turbo) did like 250 on hp and 440 on torque, like the hummer 1 with the 4l80e or are the 1999 diesels n/a ,by the ways i would go with the 8.1 i was passing mustangs going up grades with a 23 foot 5000 pound boat, plus you have the allison on that so thats defenitely a plus

[ROD1969]

This 1999 has only 68,000kms( not miles) and they tell me this truck gets 18-21mpg, i had the 454ss truck and that is about what it was getting for milage.

[LikeaRock14]

This 1999 has only 68,000kms( not miles) and they tell me this truck gets 18-21mpg, i had the 454ss truck and that is about what it was getting for milage.

 

What gears did it have?????

[02 2500avalanche]

Ya maybe the 6.5 was getting 18-21. There is no way in Gods green earth a big block would get 18-21, not even if you took for of the plug wires off would it get that

 

Alex

[ROD1969]

1992 454ss/4spd overdrive with 4.10s, i also had 1976 with the 454 373s and it was getting 18-20mpg

[awdvkd]

You should have never sold it Rod1969. Guiness book of records would have wanted it. A 545 that gets 18-20 mpg, I would rather belive in the easter bunny.

[Colorado Kid]

Rod, do you live in Canada?

 

My 1974 GMC C2500 with 454, TH400 and 4.10 gears never even once bested 13 MPG.(US)

 

My '96 GMC C1500 5.0L, NV3500 (5 speed manual), 3.42 gears does 19-21 MPG. (US)

 

 

My '02 2WD Crew Cab Short bed D-max 6 speed does 20-22 MPG.(US)

 

I'd expect the '99 454 and the '02 8.1L to be virtually equal in MPG, and that neither would ever do better than 15 MPG.(US)

 

The '99 6.5TD would probably do 18-21 MPG (US) (depending on gearing), but any crew cab gasser at 20 MPG (US) sounds like to me.