Go Back   Thor Forums > Thor Brands and Products > Thor Motor Coach | Class A, Class B+ & Class C Motorhomes
Click Here to Login
Reply
 
Thread Tools Display Modes
 
Old 02-19-2016, 09:12 PM   #1
Senior Member
 
Brand: Still Looking
State: Texas
Posts: 3,931
THOR #2121
Cummins 5.0-liter V8 in compact DP

According to MotorHome Magazine, Tiffin is the first company to use the relatively new, small, and lightweight Cummins ISV 5.0-liter V8 diesel in a DP. I'm not in market for a Diesel Pusher, but certainly hope this is part of a broader industry trend towards offering smaller motorhomes.

In a way it seems odd to see a relatively compact and narrow DP about the same width as an Axis/Vegas when for years the trend was towards making motorhomes larger. Even the specified interior headroom at only 78-inches is a throwback. That's not to say downsizing hasn't been tried before, because I recall tiny DPs in the past. They just didn't succeed for long.

What do you think? Innovation or a mistake? And will it spread to other segments?
__________________

__________________
Chance is offline   Reply With Quote
Old 02-19-2016, 09:52 PM   #2
Senior Member
 
Baddad53's Avatar
 
Brand: Thor Motor Coach
Model: Axis 25.3
State: California
Posts: 431
THOR #2526
Traded in my 39 ft DP for 25.3 Axis but that's just me and my wife. Looked at the MB version but the chassis costs a premium and my Ford V10 (E450) is serviceable at my dealer we have used for years.
__________________

__________________
2016 Thor Axis 25.3 w/ 2011 2dr Wrangler in tow
Demco tow bar with Patriot braking
Bigfoot Automatic Levelers.
Baddad53 is offline   Reply With Quote
Old 02-19-2016, 11:37 PM   #3
Senior Member
 
bevedfelker's Avatar
 
Brand: Thor Motor Coach
Model: 2015 Vegas 24.1
State: Pennsylvania
Posts: 1,304
THOR #2601
I had looked at some MB versions in the same size category as the Vegas 24.1 that I bought. The MBs were all about $20,000 more than the Vegas and did not have nearly the storage or fresh, black, and gray water capacities. I'm very happy with our Vegas. Perfect size for my wife & I (both retired) and we love the twin beds in the 24.1 floorplan.
__________________
Ed & Bev Felker
Retired USAF Col and retired Nurse
Traveling with Lily & Bella ('Teddy Bear' breed)
2015 Vegas 24.1 (E-350)
bevedfelker is offline   Reply With Quote
Old 02-20-2016, 01:14 AM   #4
Site Team
 
Brand: Crossroads
Model: CF32BL
State: Mississippi
Posts: 936
THOR #121
I would think Nissan would be able to service that motor, as it is the same going into their pick ups
__________________
Frank and Janet Henn
2008 CrossRoads CF32Bl pushing a 2007 Dodge 2500
Traveling with Hoover, Rainbow and Sunshine
The wonder Schnauzers
fhenn is offline   Reply With Quote
Old 02-20-2016, 01:23 AM   #5
Senior Member
 
Brand: Still Looking
State: Texas
Posts: 3,931
THOR #2121
Quote:
Originally Posted by Baddad53 View Post
Traded in my 39 ft DP for 25.3 Axis but that's just me and my wife. Looked at the MB version but the chassis costs a premium and my Ford V10 (E450) is serviceable at my dealer we have used for years.
Had your diesel pusher been much smaller (like an Axis in width and height but about 33-feet long), would it have made a difference in wanting to trade?



It will be interesting to see if fuel efficiency for this 23,500-pound GVWR DP is significantly better than other/larger DPs, and also if much better than an Axis/Vegas-size gasoline motorhome. Cummins previously predicted 20 to 40 percent better fuel economy out of this 275 HP 5.0L diesel V8 compared to a Ford gasoline V10, but I'm sure that was based on similar size and weight.
__________________
Chance is offline   Reply With Quote
Old 02-20-2016, 03:46 AM   #6
Senior Member
 
Baddad53's Avatar
 
Brand: Thor Motor Coach
Model: Axis 25.3
State: California
Posts: 431
THOR #2526
Quote:
Originally Posted by Chance View Post
Had your diesel pusher been much smaller (like an Axis in width and height but about 33-feet long), would it have made a difference in wanting to trade?



It will be interesting to see if fuel efficiency for this 23,500-pound GVWR DP is significantly better than other/larger DPs, and also if much better than an Axis/Vegas-size gasoline motorhome. Cummins previously predicted 20 to 40 percent better fuel economy out of this 275 HP 5.0L diesel V8 compared to a Ford gasoline V10, but I'm sure that was based on similar size and weight.
I got 7 to 8 mpg with DP - I am getting 8 to 10 mpg with V10.
My wife hated the size while traveling and liked it when it was parked. Only thing we gave up was washer/dryer. Plus she is driving it to releave me on trips ...she would never do that in the DP. Yes it was about size and costs. But my wife and I thought that the Axis/Vegas was just the right size (tanks and living space for us) MB based B's and C's. The ones with room we wanted had no capacity for GVWR.
__________________
2016 Thor Axis 25.3 w/ 2011 2dr Wrangler in tow
Demco tow bar with Patriot braking
Bigfoot Automatic Levelers.
Baddad53 is offline   Reply With Quote
Old 02-20-2016, 01:23 PM   #7
Senior Member
 
Brand: Still Looking
State: Texas
Posts: 3,931
THOR #2121
Quote:
Originally Posted by Baddad53 View Post
I got 7 to 8 mpg with DP - I am getting 8 to 10 mpg with V10.
My wife hated the size while traveling and liked it when it was parked. Only thing we gave up was washer/dryer. Plus she is driving it to releave me on trips ...she would never do that in the DP. Yes it was about size and costs. But my wife and I thought that the Axis/Vegas was just the right size (tanks and living space for us) MB based B's and C's. The ones with room we wanted had no capacity for GVWR.
That's quite an improvement.

If Cummins is correct about their 20 to 40 percent improvement over a V10, it would suggest your 8 to 10 MPG could become 10 to 14 MPG if an Axis-size motorhome had a 5.0L diesel V8. And that sounds realistic compared to Winnebago Class A on Sprinter chassis that reportedly get as high as 17 MPG (granted they are slightly smaller and lighter than Axis).

What I don't get about diesels is buyers' acceptance of low power-to-weight ratio compared to many gas motorhomes. For example, this new Tiffin with 275 HP for 23,500-pound GVWR would be the same as Ford installing a 3.2L 185 HP inline-5 in an Axis. That would also make an Axis close in power to a 3.0L Sprinter V6. Would that seem adequate after driving a 305 HP V10?



By the way, I agree the larger Mercedes Class A on Sprinter chassis is a little low on GVWR for the way it's built. I also don't like the narrow rear track for such a tall motorhome, or the limited places to get it repaired. We do like the overall size and build quality which appear very good; although higher quality should be expected at that price.
__________________
Chance is offline   Reply With Quote
Old 02-20-2016, 02:02 PM   #8
Senior Member
 
dstankov's Avatar
 
Brand: Entegra
Model: Entegra Accolade 37TS
State: Virginia
Posts: 3,363
THOR #1469
The problem I have with the Tiffin concept is the coach riding on "Tiffin's proprietary PowerGlide chassis". Who can repair that chassis when there is a problem and what is the chassis warranty? My nearest Tiffin dealer has a reputation for being great on sales and lousy on service. They are also a Thor dealer.

You can talk all you want about HP to weight ration but unless you know the specs of the entire power train you don't have any idea what the performance will be. What is the transmission gearing, what is the gear ratio of the rear end? Yes you may have an increase in "engine" performance over gas but what is the overall performance of the power train and chassis combined?
__________________

__________________
Dave
US Army (Ret)
Chester, VA
2020 Entegra Accolade 37TS
FMCA - F432054
dstankov is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Thor Industries or any of its affiliates. This is an independent, unofficial site.




All times are GMT. The time now is 02:32 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0 PL2
×