PX8 fuel economy

[Polarbear6]

Hi
Wondering if anyone has info on
Peterbuilt 335 with Allison and PX8
Wondering about fuel economy a guy could expect

 

[layoutshooter]

HI! Welcome to the club.

I can't help with your question but those who know will want to know gear ratios etc to better answer your question.

 

[Polarbear6]

Hi PX 8 with Allison 3000
5.57 rear axel

 

[davekc]

Basically a Cummins. 8.5 to 9 is what I would expect. Push it hard and 7.5 to 8

 

[Daffyduck528]

How about an mx-13? Ultra shift. No idea on rears, I guess whatever I spec...

 

[davekc]

Not sure of your application but industry reports are basically 7 with a tractor and ultrashift.

 

[Daffyduck528]

Oh, sorry Dave, I forget that not everything is a straight truck in this industry.

I'm looking at a sst100 from bolt on a cascadia. I'm having trouble getting my salesman to respond to my questions and minor issues. He'll respond but it takes 2-3 weeks. So, I was looking at Bolts website and they have a kenworth t-680 roof mold already. I'm thinking about going that route. It would be a single rear axle with a tag axle (behind the drives, not in front). To get the correct bbc truck I have to go with the mx13, they require the long nose for even the isx12. I'm curious how well this truck would perform. Would it get good mpg? 21' refer box.

 

[Daffyduck528]

Any advice or thoughts on this setup or engine would be greatly appreciated. It'll be another truck in my small fleet. I won't be driving it, it'll be for a team I already have.

 

[KickStarter6]

Oh, sorry Dave, I forget that not everything is a straight truck in this industry.

I'm looking at a sst100 from bolt on a cascadia. I'm having trouble getting my salesman to respond to my questions and minor issues. He'll respond but it takes 2-3 weeks. So, I was looking at Bolts website and they have a kenworth t-680 roof mold already. I'm thinking about going that route. It would be a single rear axle with a tag axle (behind the drives, not in front). To get the correct bbc truck I have to go with the mx13, they require the long nose for even the isx12. I'm curious how well this truck would perform. Would it get good mpg? 21' refer box.

The T680 with mx13 does seem interesting especially with the factory 76" sleeper

 

[Daffyduck528]

The T680 with mx13 does seem interesting especially with the factory 76" sleeper

I agree except I would be putting a 100" bolt on it but still interesting.

 

[KickStarter6]

I agree except I would be putting a 100" bolt on it but still interesting.

Lol that's beyond my current price range but that would be so nice. That would be a good looking truck if I do say so myself inside and out.

 

[Daffyduck528]

Lol that's beyond my current price range but that would be so nice. That would be a good looking truck if I do say so myself inside and out.

I believe so as well. Just gotta determine the mpg and the quality of that paccar engine. I'm still nervous about going that route.

 

[desk_drvr]

Drove a 2012 Cascadia SST100 DD13 450hp ultra shift 3:21 gears. Ran 11-12 mpg consistently. Our to speed was 60 to get this mileage. Why the lift axle to the rear? That configuration tends to push weight to the front axle, where as the pusher configuration takes weight off the front axle. These trucks tend o be heavy on the front with the big sleeper. Was recently given a weight slip for a new Cascadia no lift axle, Full of fuel, no drivers, gear, or water 11,990 on the front axle. Out truck with fuel, drivers, and gear ready for freight was around 13,800 with axle up and just under 12,000 with axle down. Have to watch bumper to back of cab length to get 22' box and be at 40' oal. Don't know dealer who won't return calls but I have a guess. Try Bobby Snyder at Fyda I have been dealing with him this year always returns calls and gets me the answers to the questions I ask.

 

[desk_drvr]

Hi PX 8 with Allison 3000
5.57 rear axel

Those gears sound to low I just bought M2s (daycab town trucks) with Cummins/Allison combo they are running 4:10 gears. Also have a Cascadia long haul Truck DD13/ Allison 4:10 gears. Wont buy another Allison for long haul Ultra Shifts are beating the Allison by 1mpg.

 

[Daffyduck528]

Drove a 2012 Cascadia SST100 DD13 450hp ultra shift 3:21 gears. Ran 11-12 mpg consistently. Our to speed was 60 to get this mileage. Why the lift axle to the rear? That configuration tends to push weight to the front axle, where as the pusher configuration takes weight off the front axle. These trucks tend o be heavy on the front with the big sleeper. Was recently given a weight slip for a new Cascadia no lift axle, Full of fuel, no drivers, gear, or water 11,990 on the front axle. Out truck with fuel, drivers, and gear ready for freight was around 13,800 with axle up and just under 12,000 with axle down. Have to watch bumper to back of cab length to get 22' box and be at 40' oal. Don't know dealer who won't return calls but I have a guess. Try Bobby Snyder at Fyda I have been dealing with him this year always returns calls and gets me the answers to the questions I ask.

I'm only doing a 21' box because of oal requirements. Also, the tag axle is because the kW has a lot longer nose on it than a cascadia and I'm going with a little shorter wheel base than what's on the sst100 cascadia's. It'll have like an 11' or 12' rear overhang with the lift up and 8ish with the lift down. This helps me run on 2 axles most of the time, something I can't do with a pusher. The math on the weight distro works out on this model, it's not really possible though on a cascadia 113.

 

[T270_Dreamin]

Basically a Cummins. 8.5 to 9 is what I would expect. Push it hard and 7.5 to 8

These trucks should be at 12-13 mpg by now, what is the hold up. I mines well just stick with a volvo d11 lowest hp and drive it slow with the cruise on.

 

[str8trk]

We're running a '14 T660 with an MX-13 / Ultra-shift ... Single axle / 22' reefer box. You should expect better than 10.0 mpg once the engine gets broken in a little ... We had several emissions sensor problems with ours during the 1st 10,000 miles ... No issues since. We have the HP on ours dialed in at 380 ... Plenty of power. Overall, we're happy with the performance thus far.