2011 400 isl

[cedarshack]

Hi there,
Looking for opinions.
We are looking at purchasing a 2011 coach with the 400 ISL engine. We have been told that it has 1st stage emissions. Has this dramatically changed the mileage, or the engine in a negative way? Should we look at a pre-emission coach?
Also looking at a 07 with the same engine.

Thx 1st time coach purchasers

[Steve Ownby]

Originally Posted by cedarshack

Hi there,
Looking for opinions.
We are looking at purchasing a 2011 coach with the 400 ISL engine. We have been told that it has 1st stage emissions. Has this dramatically changed the mileage, or the engine in a negative way? Should we look at a pre-emission coach?
Also looking at a 07 with the same engine.

Thx 1st time coach purchasers

1st stage emissions is a totally meaningless statement. Someone is just making stuff up. An '11 diesel coach most likely has a DPF (diesel particulate filter). which was mandated for all engines built after 1/07. It most likely also has the DEF system and there will be a tank on board which must be filled will DEF fluid. This was on all Cummins engines built after 1/10. Most of the DEF equipped ISL engines were rated at 450 hp. Since this is a 400 engine it may have been built before 1/10 and does not have the DEF system. There has been some level of emissions equipment on Diesel engines since '04.

I recommend that you not base your purchase decision on the level of emissions equipment.

[cedarshack]

Thanks for that information Steve,
We have had a camper, trailer, 5th wheel, and now looking at full timing in a coach. We are a bit overwhelmed with all the dealers and their info.
Also there is a lot of different coaches and options.
Any information/opinions are appreciated.
Thx
Nick

[Steve Ownby]

Originally Posted by cedarshack

Thanks for that information Steve,
We have had a camper, trailer, 5th wheel, and now looking at full timing in a coach. We are a bit overwhelmed with all the dealers and their info.
Also there is a lot of different coaches and options.
Any information/opinions are appreciated.
Thx
Nick

Hey Nick,

My wife and I have lived in our coach full time for 6 years now and I recommend the life without reservations.

Don't get in any hurry and learn everything you can. Decide what is really important to you and then get out and look at a lot of coaches.

It's a lot of work but also fun and exciting.

Good luck and safe travels.

[moisheh]

There has not been a 400 ISL since 2007. When they went to the DPF the HP was upped to 425. Then it became 450.

[dengraham]

Moisheh,
The 2013 Winnebago Journey and Itasca Meridian still have the ISL 400.

[moisheh]

Sorry. My mistake. I was sure that all the mfrs. were using the 400 HP version. I wonder why Winnie chose not to? Trying to cut corners or is there some other reason?

[MJFZ]

Originally Posted by dengraham

Moisheh,
The 2013 Winnebago Journey and Itasca Meridian still have the ISL 400.

My 2012 Newmar Dutch Star is also using the ISL400. In 2012 Newmar used the 450 HP version on coaches with tag axles. In either HP the torque is the same.

[dengraham]

MJFZ,
So what is the difference if the torque is the same?? Does the additional horsepower get you to the peak torque faster?? They both pull at 1250 torque which everyone says is all that matters with the diesels but I never really understood why? You would think with the lower horsepower the mileage would be a little higher?

[MJFZ]

Originally Posted by dengraham

MJFZ,
So what is the difference if the torque is the same?? Does the additional horsepower get you to the peak torque faster?? They both pull at 1250 torque which everyone says is all that matters with the diesels but I never really understood why? You would think with the lower horsepower the mileage would be a little higher?

Excellent points, and honestly I don't confidently know the the answers. Looking at Cummins data on both engine configurations http://cumminsengines.com/uploads/docs/4971281.pdf and http://cumminsengines.com/uploads/docs/4971280.pdf peak HP for both configurations are reached at the same 2100 RPM. If the definition of HP = Torque x Speed/5252; you would think both engine configurations having the same torque at the same speed would have the same HP. I am sure there are folks on this forum, who has the insight I am missing.

Mike

[Steve Ownby]

Originally Posted by MJFZ

Excellent points, and honestly I don't confidently know the the answers. Looking at Cummins data on both engine configurations http://cumminsengines.com/uploads/docs/4971281.pdf and http://cumminsengines.com/uploads/docs/4971280.pdf peak HP for both configurations are reached at the same 2100 RPM. If the definition of HP = Torque x Speed/5252; you would think both engine configurations having the same torque at the same speed would have the same HP. I am sure there are folks on this forum, who has the insight I am missing.

Mike

The often quoted opinion that torque is all that matters in a DP is simply not true. It is true that torque is the force that is measured and the hp rating is calculated from that. Torque is the twisting force that is applied to the drive shaft and ultimately the wheels. Since hp is calculated from torque and rpm the only way for hp to increase but torque remain the same is for the torque curve to be flatter and torque at the upper end of the range where hp is produced is higher. Torque may get you moving but hp is what keeps your speed up on that mountain climb.

[dsbear]

Torque is a force applied over a distance thus ft-lbs. So as Steve said the force of turning the fly wheel. Horse power is defined as in ability to lift 3300 lbs 1 ft in 1 minute. Thus horse power is what applies the force to create torque.

[JMonroe]

My dad, a mechanic, explained horsepower and torque to me many decades ago as:

"Torque is how much work an engine can do, horsepower is how fast it can do it"

[GreaTOne65]

J Monroe, that was a great explanation, one of the best ever.