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Old 08-06-2014, 12:11 PM   #15
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6.7 ltier 340 HP 2011 340 hp Cummins.with DEF.

Love it. Plenty of power great gas mileage, DEF is great, no fumez, burns very little.

9 to 11 MPG towing Chevy Avalanche 4WD.


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Old 08-06-2014, 01:20 PM   #16
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Another way to look at engine/torque number is, look backwards.

The coaches of years past seem to do OK with less power
so way do we need more today?

Where I live fuel costs have not gone down and I can get by
without running 'full out'. I don't race my rig down the highway.

2006 Monaco Diplomat Atrium model, 41'
Cummins ISL-400HP CM850
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Old 08-07-2014, 07:41 AM   #17
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Thanks for the replies. The year is 2004. I talked to freightliner and they also said this engine is before some of the new emissions requirements so it will get more of what it has to the wheels although they didn't mention the fact that the side mounted radiator takes some hp.
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Old 08-07-2014, 12:06 PM   #18
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My coach has a 300hp/950tq ISC with a side radiator and it will (not towing) pull any 6-7% grade at 1900rpm in 4th gear (about 47mph). I've thought about seeing if it could be re-mapped to 350/1050 (the transmission will take it) because it's ***THAT*** close to carrying 5th gear on a lot of hills.

I bet towing up grades you will still do a solid 45-50mph and on the flats you can haul the mail as fast as you want.

The Green Machine -- 2000 Mountain High Coachworks Summit (Spartan chassis / Cummins ISC)
...and F-Troop: Fearghus, Fiona, and Frankie (Cairn Terriers)
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Old 08-07-2014, 12:44 PM   #19
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Yep, what Skip said. All comes down to power to weight ratio. And do the math both with HP and Torque. Above 100lbs per HP, and most are OK with what they have.

Good general info by all that shared, but that power to weight, is coach specific.

Also I believe the ISC is 8.3 vs 8.1 (not a big deal, but I think it's the 8.3).

The ISC is a well respected engine. In 2004, you could have an engine designed specifically for pre ULSD. If so, then consider some preventative maintenance on swapping out the fuel line to the generator, if diesel, as the ULSD did cause pin holes in the older fuel lines. I would also look into add additives, or not. (I'm a 2004 model, with a 2003 year built Cummins ISL CAPS pre ULSD engine. I run Optilube in each tank, as added lubricant to the fuel system.)

As mentioned, the exhaust manifolds can need replacing on that era ISC. I think I read that after market ones are available, that make this a one time thing.

You've heard this many times on this and other boards, buy the house 1st, chassis and engine second. If this coach meets your needs, and has good documented maintenance - go have some fun!
04 CC Allure 40' Tag, ISL370 7.5-8 MPG, depending on many variables.
(And, 99% of the time, I'm pleased with the power to weight ratio...)
Roo II is our 04 Country Coach Allure 40'
OnDRoad for The JRNY! Enjoy life...
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Old 08-08-2014, 05:53 AM   #20
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I have the 350 ISB XT in my Discovery which is 42 feet pulling a 5000 lb toad. I often travel with a friend that has a 450 ISL in a Revolution. We went up to Colorado, and I was able to keep right on his tail on every steep grade. I am really thinking engine size is the least important factor except when you get into the real big blocks. I drove in another buddy's ISX Heritage, and that thing felt like a sports car, except it has a 200 gal fuel tank for a reason!
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Old 08-08-2014, 10:43 AM   #21
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350 cummins power

Originally Posted by kongmen View Post
Just found out that the winabago Vectra that I'm looking at has a 350 commins in it (from another thread). I just wanted to get opinions from other 40' motorcoach owners be it winabago or other wise on the performance of this size motor. We will be pulling a Toyota camry. Thanks in advance.
Hello I'm Lee and we have owned several class A's (gas then diesel) over 25 years. We had a 1999 Monaco Diplomat 38ft single slide (and pulled a Toyota Camry) it was underpowered(275HP cummins) but it still made it thru 4 kids and 10 years of enjoyment! We purchased another Monaco last year from a friend who purchased it new. A 2003 Monaco Camelot 40ft 3 slide 350HP cummins and we pull (via towdolly a Camry also), We can definitely tell the 75HP diff and go up the hill a little faster AND accelerates fine from hiway on ramps into traffic, but, like my wife says to me (a former racer) SO WHAT IF THE 500 HP GUY CAN GO OVER THE MOUNTAIN 5 MINUTES FASTER ,WE'LL CATCH HIM IN TRAFFIC!!! Our coach has 65k miles and the motor will outlast us!!! Just keep it serviced at a reliable shop and ENJOY!!! (ALWAYS check tire pressure before trips because blow outs are NOT fun) We also just replaced the exhaust manifold. cost $500 deductible with good Sam extended warranty!!!!
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Old 08-08-2014, 04:23 PM   #22
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Just purchased a 2004 Horizon (same as Vectra) in April and have no complaints about power towing a 2012 Silverado (5700#) but, fuel mileage is only 6.5. Freeway speeds are 63 mph and normal western US terrain. My 2002 Horizon with the 330 Cat got 8.1 towing the same Silverado. Also had almost the same horsepower to weight ratio and about 200 more foot pounds of torque. HP to weight ratio (GVWR for 2002=12.7 and for 2004=11) results in a 20% increase in fuel consumption. I must have a problem with my ISC. I'm going to straightpipe the exhaust and see if that helps. When I was looking, the 400 ISL wasn't offered in 2004 but got a good deal on the coach. I wouldn't let ISC bother you. Look at the computer on the prospective coach and check out the MPG. Good Luck
2004 Horizon 40AD/ISC 350/2012 SILVERADO or 2008 Chevy HHR/Demco/Vmspc/FMCA-F394912/SKP-115085/2004 Can-Am Outlander/2013 Polaris RZR
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Old 08-09-2014, 05:12 AM   #23
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We pull a loaded Silverado. ~7-7.5 mpg. It will tow at the speed limit east of the divide. It slows down in the Rockies.
Jim and Jennie, Cats=Bittles and Potter, 2000 Dynasty 350 ISC
2013 Silverado 4x4 Towed with R1200GS in bed.
PROV23:4 Do not wear yourself out to get rich; have the wisdom to show restraint.
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Old 08-09-2014, 09:09 AM   #24
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Originally Posted by kongmen View Post
Just found out that the winabago Vectra that I'm looking at has a 350 commins in it (from another thread). I just wanted to get opinions from other 40' motorcoach owners be it winabago or other wise on the performance of this size motor. We will be pulling a Toyota camry. Thanks in advance.
Not enough information. Is it an ISB, ISC or ISL?
2014 American Eagle 45T
DD 500
Pulling a Honda CRV
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Old 08-09-2014, 09:28 AM   #25
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My last coach was an 01 Monaco Dynasty. It had a 8.3 ltr 350hp Cummins Turbo Diesel in it. I towed my 13' Ford F150 back from Alberta to BC through 2 mountain passes at 55 mph and averaged 9.3 mpg. Higher speeds in Alberta sucked the fuel. On grades through the mountains in cruise control, it would drop to about 47 mph. Without cruise on, on two steep grades, it would only do just over 40 mph so I kept with the cruise control the remainder of the trip. On the flats, I never knew my truck was behind me. I wouldn't hesitate on buying a unit with a 350hp Cummins.
Les (RVM12), Bonnie, Morgan and 4 leggers Bella & Bruce
2010 Forest River Cardinal 3450RL 40' Full Body Paint- 2015 Ram 3500 Laramie 6.7 ltr Turbo Diesel, 68RFE Trans. 4x4 SRW SB Pullrite 2900 18K FMCA-420438 Good Sam
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Old 08-09-2014, 10:11 AM   #26
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300 HP Cat

Our 40' 2000 Winnebago only has the 300 Cat and we are pulling a 1973 VW Bug average 9 to 10 mpg yes I could use more power but coming out of Laughlin NV a couple of years going back to LA a Motorhome with 400hp passed me on the grade flew by me and then 20 miles down the road I pulled into a rest stop and pulled next to the 400 and when I got out I said to the guy I new you would fly by me but he said look we both here now aren't we, and at 6 to 7 mpg I think I would rather have the 300 hp.
Look most trucks on the highway run 350 to 500 hp but most are running 80,000 and they do just fine.
2000 Winnebago Ultimate Advantage 40J Blue Ox Towing a 1973 VW Bug
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Old 08-09-2014, 11:14 AM   #27
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my isc 350 has plenty of power that i have not experienced a scenario prompting me to think i need a bigger engine. in most flat roads or small slopes, i ran economy mode, no heavy breath from the engine.
2000 Country Coach Intrigue 40'
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Old 08-09-2014, 08:36 PM   #28
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Do not be afraid of a side radiator. The only time you will lose power is when the fan comes on and it will likely be on less than on a rear radiator. Side radiators tend to cool better and allow better access to the rear of the engine for servicing and repairs.
I have a 350 ISC in a 33000 lb coach and it purrs along just fine. On steeper grades it slows a little more than I would like but it definitely gets the job done. The good side of that is I average about 8 mpg over all.
They are a great engine period.

Dennis & Marcie & Hook The Jack Russell, 2001 HR Imperial 38wds 350 Cummins, 07 Chevy Trailblazer/Blue Ox/Ready Brake, 04 Dodge 3500 Cummins,
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power, cummins

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