Vortec 6.0 liter gas mileage

GMC FAQ » GMC Truck » Vortec 6.0 liter gas mileage

Question:

I have a 2002 2500HD, 6.0L, 4.10, extended cab short bed w/ 4WD. Around town I’m getting about 13. On a recent long trip with lots of highway miles, I got around 15 — even w/ 900 lbs of empty trailer. Mark I’m looking at buying an ‘02 2500HD 4×4 ExtendedCab LT with the stock 6.0 litre Vortec engine and auto tranny. Can anybody provide real-life gas mileage figures?? Thanks, Mike

Response:

I have a 2002 gmc 2500hd, I sure would like to get 12-14 I seem to get about 10-11.5 on a good day. And as low as 8 pulling a 28′ camper although that was a windy day.

Response:

MR It has just over 3K miles on the clock so I’m ready to go whenever the unit comes in. I’ll be happy if she gets around 10 MPG pulling the fifth-wheel. Pretty bad being happy with 10 MPG!!! Kevin

Make sure you do the 500 or so miles breakin before towing. I’m sure it will do fine on the 87. MR I’ll take another read through the manual to see the 87 octane info. I’ll find out in a few weeks what she does pulling a new 31′ fifth-wheel. It should be around 8,000 lbs. once loaded up for camping. Kevin Kevin, FWIW, the folks at the chevy dealer told me when I drove mine out to never put anything in the tank other than 87 octane. Reason stated was that the computer would try to adjust for the difference and if you switched back and forth would result in poor performance. I think the manual states that also. I have had very good performance with my 2500HD, 6.0 towing a 7k lb. travel trailer especially in the mountains. MR JJ, Curious to know what octane you are running as well. I always use 87 unless towing something heavy. My 2500HD has been getting a solid 13.5 MPG average with city/hwy, but it’s probably heavier on the city side. I’ll see what a flat out highway run does shortly. It has just over 3K miles on it now so the computer should be done making its shifts on the mixes by now. This is right on what my ‘95 Yukon used to get doing the exact same type of running and it had the TBI 5.7L w/ 3.42 rear 2WD! That used to do around 17 MPG on straight highway runs and 12.5 MPG towing a 2,800 lbs. pop-up. I can’t complain at all with the slightly larger engine and lower gears…. 2500HD, 6.0L w/ 4.10, 2WD, Ext. cab short bed Kevin 2002 2500HD 4X4, 6.0L auto – 4.11’s 1071Mi ~14.5 combined bought new had it 12 days now. Traded my 2001 dodge 1500 5.2 4X4 bought new had it 9 months, 27,000 mi ~15.6 mpg combined 92 ford F250HD 4X4, 460cuin 5spd 4.11 168K mi (totaled in 2001) 14mpg highway, 10 city. JJ I’m looking at buying an ‘02 2500HD 4×4 ExtendedCab LT with the stock 6.0 litre Vortec engine and auto tranny. Can anybody provide real-life gas mileage figures?? Thanks, Mike

Response:

Muddy00 reg cab, extended or crew (4×4?) Weight of our trucks is what the differences in our mileage probably is. Mine is a Reg cab 6.0 4×4 2500hd auto, 4.11. 13 – 14.5 combined so far.. JJ

I have the gmc 6.0.

Response:

I have the gmc 6.0.

Response:

I just made an interstate run from Atlanta to Florence SC with my 2001 GMC 2500HD4X4 6.0. Mileage was 15.03 at 70-75 mph (except around Columbia). This was best ever. Timing has been lowered and shift points have been raised by dealer to cut down on spark knock. This has cut down on power and drivability. Still have to run “plus”. 8300 miles on truck. I have one of the pistonslap motors and it irritates me no end. You ought to hear this puppy knock on start- up! Especially on a cold morning! It isn’t as smooth or as quiet (even when warm) as when it was new. It started this at less than 3000 miles. Buy one. You may get a good engine, you may not. It’s only 35k and a knot in your belly if you don’t! And you get to be entertained listening to dealer and gm rep bs! By the way, I run Mobil 1, which may help a little on gas mileage. Overall, I think I’m getting 12-13 mpg. Around 8.5-9 towing a 3 horse gooseneck trailer. I’m a conservative driver. If I hadn’t had such a bad experience with a 5.7 diesel, I think I would have bought a duramax. But they have a few problems, too. Mark

Response:

Kevin, I’ve been using 87, have not towed yet, but the Daughter’s looking for a 2-horse trailer for me to pull for her :^) JJ

JJ, Curious to know what octane you are running as well. I always use 87 unless towing something heavy. My 2500HD has been getting a solid 13.5 MPG average with city/hwy, but it’s probably heavier on the city side. I’ll see what a flat out highway run does shortly. It has just over 3K miles on it now so the computer should be done making its shifts on the mixes by now. This is right on what my ‘95 Yukon used to get doing the exact same type of running and it had the TBI 5.7L w/ 3.42 rear 2WD! That used to do around 17 MPG on straight highway runs and 12.5 MPG towing a 2,800 lbs. pop-up. I can’t complain at all with the slightly larger engine and lower gears…. 2500HD, 6.0L w/ 4.10, 2WD, Ext. cab short bed Kevin 2002 2500HD 4X4, 6.0L auto – 4.11’s 1071Mi ~14.5 combined bought new had it 12 days now. Traded my 2001 dodge 1500 5.2 4X4 bought new had it 9 months, 27,000 mi ~15.6 mpg combined 92 ford F250HD 4X4, 460cuin 5spd 4.11 168K mi (totaled in 2001) 14mpg highway, 10 city. JJ I’m looking at buying an ‘02 2500HD 4×4 ExtendedCab LT with the stock 6.0 litre Vortec engine and auto tranny. Can anybody provide real-life gas mileage figures?? Thanks, Mike

Response:

Do you have the 8.1 or the 6.0? Could be that it is a gmc and not a chevy.g MR

I have a 2002 gmc 2500hd, I sure would like to get 12-14 I seem to get about 10-11.5 on a good day. And as low as 8 pulling a 28′ camper although that was a windy day.

Response:

I’m looking at buying an ‘02 2500HD 4×4 ExtendedCab LT with the stock 6.0 litre Vortec engine and auto tranny. Can anybody provide real-life gas mileage figures?? Thanks, Mike

Response:

‘02 2500HD, 6.0L 4.10 rear, ext. cab short bed, 2WD, 3,000 miles on it = Averaging 13.5 MPG city/hwy I’ll get a good idea of what ALL hwy will do shortly. My Dad has the ‘02 2500HD 8.1L w/ 4.10 rear Allison tranny, ext. cab, long bed and he is getting in the low to mid 12’s on the hwy! More torque, but it is harder on the petrol!

I’m looking at buying an ‘02 2500HD 4×4 ExtendedCab LT with the stock 6.0 litre Vortec engine and auto tranny. Can anybody provide real-life gas mileage figures?? Thanks, Mike

Response:

My dad has a one ton with a 14 ft flatbed and the duramax and a six speed and he gets 25 mpg

Response:

I’m looking at buying an ‘02 2500HD 4×4 ExtendedCab LT with the stock 6.0 litre Vortec engine and auto tranny. Can anybody provide real-life gas mileage figures?? Thanks, Mike

Response:

2002 2500HD 4X4, 6.0L auto – 4.11’s 1071Mi ~14.5 combined bought new had it 12 days now. Traded my 2001 dodge 1500 5.2 4X4 bought new had it 9 months, 27,000 mi ~15.6 mpg combined 92 ford F250HD 4X4, 460cuin 5spd 4.11 168K mi (totaled in 2001) 14mpg highway, 10 city. JJ I’m looking at buying an ‘02 2500HD 4×4 ExtendedCab LT with the stock 6.0 litre Vortec engine and auto tranny. Can anybody provide real-life gas mileage figures?? Thanks, Mike

Response:

I’ll take another read through the manual to see the 87 octane info. I’ll find out in a few weeks what she does pulling a new 31′ fifth-wheel. It should be around 8,000 lbs. once loaded up for camping. Kevin

Kevin, FWIW, the folks at the chevy dealer told me when I drove mine out to never put anything in the tank other than 87 octane. Reason stated was that the computer would try to adjust for the difference and if you switched back and forth would result in poor performance. I think the manual states that also. I have had very good performance with my 2500HD, 6.0 towing a 7k lb. travel trailer especially in the mountains. MR JJ, Curious to know what octane you are running as well. I always use 87 unless towing something heavy. My 2500HD has been getting a solid 13.5 MPG average with city/hwy, but it’s probably heavier on the city side. I’ll see what a flat out highway run does shortly. It has just over 3K miles on it now so the computer should be done making its shifts on the mixes by now. This is right on what my ‘95 Yukon used to get doing the exact same type of running and it had the TBI 5.7L w/ 3.42 rear 2WD! That used to do around 17 MPG on straight highway runs and 12.5 MPG towing a 2,800 lbs. pop-up. I can’t complain at all with the slightly larger engine and lower gears…. 2500HD, 6.0L w/ 4.10, 2WD, Ext. cab short bed Kevin 2002 2500HD 4X4, 6.0L auto – 4.11’s 1071Mi ~14.5 combined bought new had it 12 days now. Traded my 2001 dodge 1500 5.2 4X4 bought new had it 9 months, 27,000 mi ~15.6 mpg combined 92 ford F250HD 4X4, 460cuin 5spd 4.11 168K mi (totaled in 2001) 14mpg highway, 10 city. JJ I’m looking at buying an ‘02 2500HD 4×4 ExtendedCab LT with the stock 6.0 litre Vortec engine and auto tranny. Can anybody provide real-life gas mileage figures?? Thanks, Mike