Isata 5 vs Force HD Pulling

[Webefine]

But your comparing your DX3 to a gas powered motor home. The question was comparing two diesel RVs with similar horsepower.

[dlfishing]

Originally Posted by Webefine

But your comparing your DX3 to a gas powered motor home. The question was comparing two diesel RVs with similar horsepower.

True but to me it’s the torque that counts not HP, that’s the big advantage of diesel.
My diesel Jeep has 100 hp less than my last, HEMI, Jeep with the same towing capacity.

[Webefine]

Believe what you like!

[rskeans]

The problem I had with my V10 was it just did not have enough torque at the low RPM's to get the load moving up the mountain. Once I got the RPM's above maybe 3000 it hauled. The formula for HP includes RPM x Torque divided by something like 5252 (Don't remember). If you don't have RPM you don't have HP. So at low RPM's you need Torque. Diesel's have torque at low RPM's like when starting up a grade from a stop. Diesel's have a low high RPM range so they typically show low maximum HP. But they sure have the torque to get the load moving.

[The Renegade]

I dont know how to explain it in proper terms rather its hp or torque but I used to use gas 3/4 ton trucks at first for pulling and they did ok as long as you kept the rpms up. You had to run them pulling to where they felt like they were gonna blow up but never did. I switched to diesel when Ford came out with the International 7.3. It was not fast but it would pull.

Newer trucks have more HP and I think the new Ford is over 1000lb torque. I bought a new "17 Ford and sold it with 4k miles on it. I can tell you it would run like crazy but fuel mileage was terrible and the size of the truck was like a bus so I sold and went back to Ram Cummins and they just like to run and pull something. Thats when they seem to be comfortable.

There have been some good discussion on this and if we had took a poll, maybe the Isata 5 was the winner. Didn't go back and count but good conversations.

[dlfishing]

Originally Posted by Webefine

Believe what you like!

One other point.
The DX3 doesn’t actually weigh 33k and I doubt the Force does. More like 26k
I don’t know the actual weight of the Isota 5 but I’ve read that it’s close to capacity.
Try the math with the actual weights and see the results.

[The Renegade]

Maybe Brian will chime in with some actual weights or if somebody has checked their rigs.

[letsgorving]

Question for this engine discussion.....We had a 40ft tiffin DP with same weight, hp and torque of our DX3, but the DP went up the hills faster and you didnt have to floor it. Anybody explain to me why that is, see specs below.

2018 DX3- 8.9L ISL Turbo diesel 350hp/1000torque, 3200 allison tranny
2010 Tiffin Phaeton 40ft DP- Spartan cummins ISC 8.3L 360hp/1050torque, 3000allison

Just trying to understand how it all works

[Magnatudes]

Originally Posted by letsgorving

Question for this engine discussion.....We had a 40ft tiffin DP with same weight, hp and torque of our DX3, but the DP went up the hills faster and you didnt have to floor it. Anybody explain to me why that is, see specs below.

2018 DX3- 8.9L ISL Turbo diesel 350hp/1000torque, 3200 allison tranny
2010 Tiffin Phaeton 40ft DP- Spartan cummins ISC 8.3L 360hp/1050torque, 3000allison

Just trying to understand how it all works

Axle ratio & tire size may be a factor. Actual weight of the RV loaded.
I had an 8.9L ISL pusher but it was 400HP. Dunno about the differences & warranties but you might be able to have Cummins reprogram the engine control module to boost yours to 400HP. Back when I had this I was told that the 400HP was only a program change. Dunno if there was anything else different like fuel pump or turbo size. My ISL hauled buns towing an 8000lb diesel jet boat uphill passing folks like they were standing still. Also pulled a 12,000lb 24ft enclosed trailer with ease. You might also check to make sure your tranny is not in economy mode (if you have that) when comparing to the ISC.

[The Renegade]

Originally Posted by letsgorving

Question for this engine discussion.....We had a 40ft tiffin DP with same weight, hp and torque of our DX3, but the DP went up the hills faster and you didnt have to floor it. Anybody explain to me why that is, see specs below.

2018 DX3- 8.9L ISL Turbo diesel 350hp/1000torque, 3200 allison tranny
2010 Tiffin Phaeton 40ft DP- Spartan cummins ISC 8.3L 360hp/1050torque, 3000allison

Just trying to understand how it all works

Easier to push than it is to pull.... LOL Just kidding. I have no clue. Thats what the thread is about. Sure wish we had a diesel expert somewhere around.

[mookieblaylock]

Interesting, as that has to be the third or fourth time I've read those same comments regarding the power/speed of the 360 or 380 horse Phaeton.

Best I can tell, the axle ratio tire size of that generation Phaeton was very similar if not identical. The only differences I can think of is that the Phaeton used the MH version of both the Allison and the Cummins. According to the Allison data sheets, the specs on the 3000MH and the 3200TRV appear to be the same. Cummins does differentiate between the MH and Medium-Duty versions of the 8.9, but I cannot figure out what those differences entail.

[jrk341]

All Ram chassic cab with a Cummins has the Aisin behind it.

[dlfishing]

Diesel Jet Boat?????

[letsgorving]

Yes would love to hear from a DIESEL ENGINE EXPERT!!!! Anybody?

Interesting for me to hear that about the Phaeton. My husband did not want to get rid of it, i was the one pushing for the Super C (and as someone else was saying on another thread, as the wife I won!!) He was tired of me complaining how i hated riding in it. LOVE the ride of our DX3. BUT it is a dog compared to that Phaeton and I have to hear about it all the time.

And not to but why with almost same engine??!!

[Magnatudes]

Originally Posted by dlfishing

Diesel Jet Boat?????

Not turbocharged but supercharged military diesel

[The Renegade]

Originally Posted by letsgorving

Yes would love to hear from a DIESEL ENGINE EXPERT!!!! Anybody?

Interesting for me to hear that about the Phaeton. My husband did not want to get rid of it, i was the one pushing for the Super C (and as someone else was saying on another thread, as the wife I won!!) He was tired of me complaining how i hated riding in it. LOVE the ride of our DX3. BUT it is a dog compared to that Phaeton and I have to hear about it all the time.

And not to but why with almost same engine??!!

Why did you not like riding in the Phaeton? Did you ever drive it?

[The Renegade]

Originally Posted by letsgorving

Yes would love to hear from a DIESEL ENGINE EXPERT!!!! Anybody?

Interesting for me to hear that about the Phaeton. My husband did not want to get rid of it, i was the one pushing for the Super C (and as someone else was saying on another thread, as the wife I won!!) He was tired of me complaining how i hated riding in it. LOVE the ride of our DX3. BUT it is a dog compared to that Phaeton and I have to hear about it all the time.

And not to but why with almost same engine??!!

Dang you got me worried about the power now. I hate to drive something that won’t pull and drops speed when it really shouldn’t.

[letsgorving]

Oh no Mountieman don't start worrying about something else!! We had the DX3 out in wyoming and it ran up all the big hills out there with 5 people inside, food, drinks for those people for 2 weeks, pulling our jku, plus we keep alot of stuff in it. It just doesn't seem to have the power the phaeton did, but that was a MH, this is a truck. Would really love to hear an explanation from someone who knows.

I drove the DP a couple times, was terrified, refused to drive anymore. Feels like a big living room going down the road, plus its like riding in a "boat" as someone put it in another thread. Good analogy for what I thought. Begged my husband to get rid of it.

[The Renegade]

Originally Posted by letsgorving

Oh no Mountieman don't start worrying about something else!! We had the DX3 out in wyoming and it ran up all the big hills out there with 5 people inside, food, drinks for those people for 2 weeks, pulling our jku, plus we keep alot of stuff in it. It just doesn't seem to have the power the phaeton did, but that was a MH, this is a truck. Would really love to hear an explanation from someone who knows.

I drove the DP a couple times, was terrified, refused to drive anymore. Feels like a big living room going down the road, plus its like riding in a "boat" as someone put it in another thread. Good analogy for what I thought. Begged my husband to get rid of it.

Oh I’m still good. Glad your concerned about my nerves. Lol. I like your posts. Straight to the point. The boat part with the DP, are you talking about it drifting around a little on the road? I kinda thought the bigger MH’s were supposed to be more stable.

[Webefine]

Back to my rationale of why I think the 5 would win. This was my set up before the DX3. The truck was a 6.7 Powerstroke with 400 hp and 800 torque, the total weight on CAT scales was 25,200 pounds. This set up was about 2,000 pounds less than what my DX3 weighs with 200 less pound feet of torque and it pulled the hills around my area (5 to 9 percent) faster than my DX3 does. Horsepower wins the race to the top of the hill, torque gets you moving and keeps you rolling down the highway.