Nbs 6.0 Performance

ABQFirefighter · August 21, 2007

Does anybody have any experience with the NBS 6.0 engine? Would like to hear info on how it does pulling/towing anything significant along with MPG numbers.

dcontarino · August 30, 2007

Does anybody have any experience with the NBS 6.0 engine? Would like to hear info on how it does pulling/towing anything significant along with MPG numbers.

I can partially answer your question, which is better than none I guess. I've had my 6.0 '08 GMC 2500HD for two weeks now, and have just over a thousand miles on it.

I've averaged 15.5 MPG so far, with the best tank being 16.9 mostly interstate @ 70 MPH, and worst tank 14.9 mostly around town/rural roads @ 45 or less MPH. These #s are calculated by hand based on fill ups.

I haven't towed anything yet, but I can tell you the 6.0L has plenty of oomph, and it sounds great. Have you read the pickuptruck.com article re: HD comparison test? The GM 6.0L came out as fastest of the gas engines overall with the exception of a couple of the towing tests. Anyhow, my only complaint so far is the kickdown from 6th gear when passing or going uphill. This may be a problem with mine (not sure) or the tranny is still learning my style, but I have to press down pretty far to get decent passing power... when it does kick down, it appears to be to 4th gear, the engine revs up to 3000RPM or so, which in many cases is too much power when you're going 45 on a main road in an urban area. I haven't tried the tow/haul mode to see if this perhaps helps the problem. And of course the tranny has a manual shift feature too, which works really well.

I read in your bio that you're HD shoppin'. I'm a Toyota convert and this truck has impressed me from day 1. I'm really happy with the quality, ride, handling, power, creature comforts, etc. This is a great daily driver, and it definitely defines "cowboy cadillac". Hope that helps ya a bit.

Dave

k3500CC8.1 · August 30, 2007

My 2007 K2500 Suburban has the 6.0L mated to the 4 speed and 4.10's. Currently right at 10k miles and best mileage to date has been 18.2mpg on a cross country trip. Average daily duties return right around 15mpg in town. The engine has very good power when the PCM decides to let you have it. This is very frustrating. Any situation when you floor the pedal results in a 4-7 second delay until you get full power. You can be cruising at 80mph on the interstate and kick it down and still get the same delay. From a dead stop you will not get full power until you pass 4500 rpms. At that point the engine becomes impressive. I will soon purchase a custom tune to take care of this.

Pulled loads ranging between 7-11K without any problem. Mileage from last trip with 11k behind me was 8.2mpg. This was over a 280 mile trip.

Basically, happy with mileage and potential power. Not happy with the little electronic computer god under the hood.

2017HD · August 31, 2007

I have an early 07HD ext cab, 4x4, 4.10 diffs that I got in March. I love the truck and with each 1000mi it gets better and better both in performance and MPG perhaps the computer is programed to release the power slowly. I now have just over 7k and things are really great solo - will tow again in a couple of weeks. MPG according to both hand and DIC is 14. I tow a 24' Arctic Fox that tips the scales at about 5700lbs. I can go down the hy at 60 in 6th on the flat with no problems but any hill and it shifts to 5th and then to 4th all maintaining 60 - the revs go up to about 3500 in 4th but I can zip up a 7% grade. Besides that area between 3 and 4k is great for power and exhaust sound. I love the tranny - at first it seemed a bit slow to downshift, but now it is getting better. What I really like is the Tow mode and the grade brakes- tap the brake and she downshifts a gear, hold the brakes on and it keeps going down - great for stopping the TT in town. I find I am using less brakes - both on the truck and TT.

dcontarino · August 31, 2007

...I love the tranny - at first it seemed a bit slow to downshift, but now it is getting better. What I really like is the Tow mode and the grade brakes- tap the brake and she downshifts a gear, hold the brakes on and it keeps going down - great for stopping the TT in town. I find I am using less brakes - both on the truck and TT.

A bit off topic but I was glad to read that I am not alone in thinking the 6spd auto is a bit slow to downshift. And I was really glad to read that it is getting better as the miles get racked up...

I, too, have been using tow/haul mode even without anything in tow - the grade braking is a great feature. Also, with the tap shift, I also find myself using the brakes less and less. Hopefully that'll lead to longer life rotors & pads!!

SS Crew · September 1, 2007

I've got an '07 GMC Sierra 2500 HD with the 6.0. I recently got a tune for my truck and it really woke it up. On the dyno I picked up 52 rear wheel horsepower and 95 ft lbs torque at 3000 rpm. That shows you how bottled up these engines are. Driving is now a pleasure, I don't have to plan on my highway passing, when I nail the pedal it downshifts, no delay.

The only unfortunate thing is that my mileage still sucks. I've been getting about 12 - 13 mpg going to work in traffic - 50 miles each way. I did make a 500 round trip and according to my DIC I only pulled 12.5 mpg, but that's running at 80 - 85 mph. I did a 6 car pass and got up to 115 mph and it was still pulling strong.

Do the right thing - get a tune it'll let out its inner beast.

Judge Smales · September 1, 2007

I've got an '07 GMC Sierra 2500 HD with the 6.0. I recently got a tune for my truck and it really woke it up. On the dyno I picked up 52 rear wheel horsepower and 95 ft lbs torque at 3000 rpm. That shows you how bottled up these engines are. Driving is now a pleasure, I don't have to plan on my highway passing, when I nail the pedal it downshifts, no delay.

The only unfortunate thing is that my mileage still sucks. I've been getting about 12 - 13 mpg going to work in traffic - 50 miles each way. I did make a 500 round trip and according to my DIC I only pulled 12.5 mpg, but that's running at 80 - 85 mph. I did a 6 car pass and got up to 115 mph and it was still pulling strong.

Do the right thing - get a tune it'll let out its inner beast.

Who did you have tune it?

SS Crew · September 1, 2007

I've got an '07 GMC Sierra 2500 HD with the 6.0. I recently got a tune for my truck and it really woke it up. On the dyno I picked up 52 rear wheel horsepower and 95 ft lbs torque at 3000 rpm. That shows you how bottled up these engines are. Driving is now a pleasure, I don't have to plan on my highway passing, when I nail the pedal it downshifts, no delay.

The only unfortunate thing is that my mileage still sucks. I've been getting about 12 - 13 mpg going to work in traffic - 50 miles each way. I did make a 500 round trip and according to my DIC I only pulled 12.5 mpg, but that's running at 80 - 85 mph. I did a 6 car pass and got up to 115 mph and it was still pulling strong.

Do the right thing - get a tune it'll let out its inner beast.

Who did you have tune it?

I had a local performance shop here in San Dimas, California do the tune. And no, he doesn't do mail orders. Have you checked with T. Byrne Motorsports, he's the U.S. Westers rep. Plus you've got 2002 model and there's ton's of exchange computers out there for those models. The '07s have a new computer in them and there aren't any exchanges floating around. There are many mail-order shops around: Nelsons, Westers, Wait4Me, etc. And there are people on this board who can tell you the pros and cons of who did their tuning. I had a Westers on my last truck, it was good, but it wasn't great, not like the day and night difference I got on this tune. But this truck was done on a dyno so the most performance could be extracted out, even though all these trucks are supposed to be tuned the same from the factory, every truck is slightly different. If you can get a dyno'd tune, that would be your best bet.

tthomass1 · September 2, 2007

8mpg average towing

I've got an '07 GMC Sierra 2500 HD with the 6.0. I recently got a tune for my truck and it really woke it up. On the dyno I picked up 52 rear wheel horsepower and 95 ft lbs torque at 3000 rpm. That shows you how bottled up these engines are. Driving is now a pleasure, I don't have to plan on my highway passing, when I nail the pedal it downshifts, no delay.

The only unfortunate thing is that my mileage still sucks. I've been getting about 12 - 13 mpg going to work in traffic - 50 miles each way. I did make a 500 round trip and according to my DIC I only pulled 12.5 mpg, but that's running at 80 - 85 mph. I did a 6 car pass and got up to 115 mph and it was still pulling strong.

Do the right thing - get a tune it'll let out its inner beast.

Who did you have tune it?

I had a local performance shop here in San Dimas, California do the tune. And no, he doesn't do mail orders. Have you checked with T. Byrne Motorsports, he's the U.S. Westers rep. Plus you've got 2002 model and there's ton's of exchange computers out there for those models. The '07s have a new computer in them and there aren't any exchanges floating around. There are many mail-order shops around: Nelsons, Westers, Wait4Me, etc. And there are people on this board who can tell you the pros and cons of who did their tuning. I had a Westers on my last truck, it was good, but it wasn't great, not like the day and night difference I got on this tune. But this truck was done on a dyno so the most performance could be extracted out, even though all these trucks are supposed to be tuned the same from the factory, every truck is slightly different. If you can get a dyno'd tune, that would be your best bet.