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huffypuff

340 hp 6.7 L

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While at Quartzsite my DW wanted to check floorplans of motorhomes. She found a floorplan she likes but i'm not confindent the engine is strong. I'm not sure that the 6.7 L 340 hp cummins with 2500 Allison can handle steep grades a 40 foot with 33,000 lbs towing a car. 

Does anyone have experience with this engine and trans setup to can give feedback?

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I think its a little small and the 2500 I think is a 5 speed.  It physically has 6 gears but the computer only uses 5 at least thats what I found out when it first came out

 

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For comparison; I have the MH in my signature, GVWR is 31,000lb. The Cummins 8.3L ISC has 350 HP and 1,075 lb/ft torque. I flat-tow a 2013 Chevy silverado that weighs approx. 5,400lb empty. I average 7.3 mpg. I slow to around 40-45 mph on hills like Mt. Eagle if nothing breaks my momentum.

Compare the HP to weight ratio for coach only, which should be 1HP to 100# as a minimum for satisfactory performance.

IMO, that MH with ISB engine will do the job, but for me would be frustrating in mountains, and interstate on-ramps.

 

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8 hours ago, RayIN said:

For comparison; I have the MH in my signature, GVWR is 31,000lb. The Cummins 8.3L ISC has 350 HP and 1,075 lb/ft torque. I flat-tow a 2013 Chevy silverado that weighs approx. 5,400lb empty. I average 7.3 mpg. I slow to around 40-45 mph on hills like Mt. Eagle if nothing breaks my momentum.

Compare the HP to weight ratio for coach only, which should be 1HP to 100# as a minimum for satisfactory performance.

IMO, that MH with ISB engine will do the job, but for me would be frustrating in mountains, and interstate on-ramps.

 

 

12 hours ago, desertdeals69 said:

I think its a little small and the 2500 I think is a 5 speed.  It physically has 6 gears but the computer only uses 5 at least thats what I found out when it first came out

 

Thanks you both have the same feeling I do but I looking for someone that has it and can tell me with their real experience. The motorhome is a 2019 but I think the engine was used for a few years now.  I didn't think I would like a v6 in a pickup but love it. 

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The transmision would be a showstopper for me if it is just using 5 gears. The 6.7 is the same basically as my 5.9. I have been nearly everywhere with no major problems. Yes you need to shift to make best use. 

To me the new coach would be a step back from your current coach.

Bill

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I have a 2018 Pace Arrow 36U.  It has the Cummins 6.7 340 hp.  The allison 2500 in mine is a six speed.  I was in Colorado and South Dakota and did not have any problems.  I was pulling a 2016 Chevrolet Colorado.  Averaged about 8.4 mpg.

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6 hours ago, JGALLEGO said:

I have a 2018 Pace Arrow 36U.  It has the Cummins 6.7 340 hp.  The allison 2500 in mine is a six speed.  I was in Colorado and South Dakota and did not have any problems.  I was pulling a 2016 Chevrolet Colorado.  Averaged about 8.4 mpg.

Thank you for your reply.  They also list the transmission as a 6 speed so I don't know how it was refered as a 5 speed. 

I like the mileage you are getting. My current coach is showing a life as 7.6 mpg. 

I like to know how your coack handle steep grades as speed and temperature. Thank you in advance. 

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I have that same drivetrain in my 15 Forza. It’s def. a six speed transmission. Just came back from Orlando without a toad I get 10.6 mpg with cruise set at 65mph. This summer I was pulling some decent hills on rt80 in PA. with a 4200# toad. I did drop to 45 mph on the hills. I was watching all the gauges and had my hand ready to downshift if engine temp climbed to high but the computer did it for me. It happened to be a 85degree day that day engine temp hit around 210 computer made necessary adjustments to transmission gear or engine fan and quickly brought temps down to normal. I was pleased with the performance. Heading to Nashville this summer so I’ll get another taste of some mountain grades. To say I would buy another DP with the same 340 ISB probably not. I probably will be moving up to 45’ model with a tag axle in the near future and will be looking for a little more towing capacity. Going from a gasser to this entry level DP was overall a move in the right direction. Don’t know if I would be able to go I the opposite direction on horsepower though but to each his own. Good luck I your search 

 

Phil

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I have a 2104 allegro RED with the 6.7 340 hp and 2500 transmission. I towed a Toyota 4 runner which was around 4500 lbs and my coach is 29500 lbs.  I traveled out west and north up into Canada. The coach did fine as far as transmission temperature, engine temperature and overall performance. Long grades slowed me down but I was always keeping up with the flow. At times some people passed me, however there were times that I passed others. I always use the shift arrows and down shift long before the transmission automatically down shifts. When I am in mountains or very hilly roads I limit the transmission to 5th gear and at times have limited it to 4th gear to reduce the slow down on long grades. I had the transmission serviced at 30,000 miles and the tech said that the fluid looked new and there were no indications of abnormal wear. With all of that said I don't have a problem driving it this way and am ok with the performance. However knowing what I know now I probably would have purchased something with at least 360hp and 3000 transmission. This is my first class A coach and I wasn't aware of the options. But it's not worth the money to trade up now because of the slight inconvenience of having to help it shift.

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I have to step back for the moment and think what ie being said here.  It appears the 6.7 640 with 2500 trans is marginal but the 6.7 360 with 3000 trans should do the job better.  I agreed that 360 is a  better option but only 800 lbs of torque.  Is there a formula of how muck torque needed to weight for grade of 6.5%?

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Puff, there is a formula that OEM’s use when pairing driveline to GCWR and GVWR. On a motorhome id be more concerned as the chassis manufacturer has no idea what the coach builder is going to install with regards to wind drag and weight.

You considering trading in for a new coach?

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The issue for me is really not the performance of the 340hp but the fact that the 2500 is at its limit. So the coach with the 340 and 2500 is limited to 33K GCWR and the only way to change that is replace the transmission with the 3000.  If I remember correctly the 2500 transmission is limited to 660lbs of input torque. So, you can not turn up the hp and torque of the 6.7 340hp without risking damage to the transmission and the GCWR can not be increased above 3300lbs.

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15 hours ago, jleamont said:

Puff, there is a formula that OEM’s use when pairing driveline to GCWR and GVWR. On a motorhome id be more concerned as the chassis manufacturer has no idea what the coach builder is going to install with regards to wind drag and weight.

You considering trading in for a new coach?

DW is looking at floor plans and of the HR we looked at the floorplan is great but I don't like being underpowered.  We looked a a Newmar Dutch Star and chassis is great with 9 L 450 hp and floor plan 95% but not planing to spend that much.  Cost almost as much as our house for 3 year old custom coach.  The HR cost less new but is comparing apples to oranges

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11 hours ago, huffypuff said:

DW is looking at floor plans and of the HR we looked at the floorplan is great but I don't like being underpowered. 

What is it you wife doesn't like about your coach? Or is it you just want something different? You could  probably get someone like Texas Custom coach to redo the interior any way you want cheaper than a new coach.

Bill

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Happy wife, happy life!  I had the 2500 & Duramax in a Chevy 2500 PU 4x4..great combo, but a 40' coach?  I think not.  Linda has the 350 CAT/3000 in her 40' DP and it's a OK combo.  For long 5-6 degree hills, she would like more than 800# torque!  Mine is 425hp at 1250...for 45', I would have preferred the 500.

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DW and I stopped looking at coaches yesterday not because of not wanted a new coach but because of the buying process and the games the sales staff plays.  We found a beatiful coach and ready to buy but they jerked us around so much that I walked out when the salesman was going to get a better deal to bat for us.  LOL  They texted a better deal when we already left and found a third coach we wanted to see.  That coach was everything we wanted so I should thank they for wasting our time.  

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I used RV Trader to find my present coach. Made them an offer, they countered, I came back and they accepted. 

You know they didn't loose any money over the deal but I also know I got a good buy.

I wrote them a check for the extended service plan and the next day I called and cancelled it for a better deal elsewhere. They were not happy when I put a stop on the check, but I was.

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