What kind of mileage do you get?

[glfirefighter144]

I've tapped the back door of 19 mpg a couple times.

Still working on the "tune" to crack that 20 mark and stay around 250 RWHP.....

I think taller tires would help me some, since it still has the 225/75s on it, 235/85s would be better for mpg I would think

 

[great white]

I think taller tires would help me some, since it still has the 225/75s on it, 235/85s would be better for mpg I would think

Depends.

I gained mpg going from 285 to 265.

Where the engine reaches torque peak is one of the factors in mpg.

So is proper speed calculation for the pcm.

Reducing rpm isn't always the right solution...

 

[benz88]

My 6.5 Is usually around 18mpg City, 20-22ish Combined and 23-24 loaded on the highway(Couple bags, Coolers and couple 3 people). But Ive got 3.42's which are perfect for the highway haha

 

[Vortec Lover]

my dad's new truck got 17.1 driving back from Wisconsin. 265/70/17 wheels, 350 TBI, 4x4 ECSB 1993

 

[great white]

My 6.5 Is usually around 18mpg City, 20-22ish Combined and 23-24 loaded on the highway(Couple bags, Coolers and couple 3 people). But Ive got 3.42's which are perfect for the highway haha

Settle down there with your non turbo-charged ***!



3:42's wouldn't do me very well with a 9000 lb 9 foot high sail hanging off the bumper anyways.......

 

[West Mi Mudder]

I used to average 17-18 with 315/75r16 and 3.73s. But niw with the Heath Diesel tune and manual wastegate, i tend to get 15-16. Thats mainly because i have a heavier foot now because the turbo makes my pants fit tight.

Sent from my SAMSUNG-SGH-I337 using Tapatalk 2

 

[benz88]

Settle down there with your non turbo-charged ***!



3:42's wouldn't do me very well with a 9000 lb 9 foot high sail hanging off the bumper anyways.......

haha.

 

[glfirefighter144]

Depends.

I gained mpg going from 285 to 265.

Where the engine reaches torque peak is one of the factors in mpg.

So is proper speed calculation for the pcm.

Reducing rpm isn't always the right solution...

and i understand that, however, increasing tire size slightly, either a 245/75 or 215/85 should help in mileage, since i generally don't run above 55 MPH{roughly 88.5 KM/H}, if i drove the truck to work on a four-lane divided highway with a 65 MPH {roughly 105KM/H} then a 235/85 should net me better MPG as the RPMs would be decreased, which also makes you think about loosing the low gear for towing since the tires are taking it away, so it's kinda iffy either way

EDIT: the truck is at ~1800 RPMs at 55 MPH with the current setup 225/75 R16s - 4.10s - NV4500

last mileage was 17.1, hoping it will go up if i convince myself to order Heaths stage 1 kit, power will improve regardless with it, decisions decisions

 

[great white]

and i understand that, however, increasing tire size slightly, either a 245/75 or 215/85 should help in mileage, since i generally don't run above 55 MPH{roughly 88.5 KM/H}, if i drove the truck to work on a four-lane divided highway with a 65 MPH {roughly 105KM/H} then a 235/85 should net me better MPG as the RPMs would be decreased, which also makes you think about loosing the low gear for towing since the tires are taking it away, so it's kinda iffy either way

EDIT: the truck is at ~1800 RPMs at 55 MPH with the current setup 225/75 R16s - 4.10s - NV4500

last mileage was 17.1, hoping it will go up if i convince myself to order Heaths stage 1 kit, power will improve regardless with it, decisions decisions

You're also not considering the added mass of larger tires.

Even a size up adds mass in the worse possible location for mpg.

Adding a couple pounds further out from the wheel rotating center is like adding tens of pounds to the vehicle itself. This is beacuase the heaviest part of the tire (belts and tread face) is further away from the center. The weight has more leverage against engine torque (you have to think of the tire as a lever bar and the center is the fulcrum). This means more throttle to accelerate it to speed, which means lower mpg.

You will lower the rpm a small amount, but you're also going to need a heavier foot.

Unfortunately, the only way to know if the trade off is going to mean better mpg is to try it. Bummer part of that is new tires ain't cheap....

 

[96-1500]

Got 16.147 L/100km (14.56 mpg) on an 822 km (510 mi) road trip. Half lightly loaded (say probably 600-1000 lbs), half unloaded. Driving @ approx 100 km/h the whole way.

Stock K2500 5.7 Vortec / 4L80E / 4.10s