Cummins ISX 600

[truckr44@yahoo.com]

I am presently looking at a motorhome with a Cummins ISX 600 in it.

I have been use to traveling the country in an 18-wheeler over all 48 lower states, on different mountain grades. The 18-wheeler had a Detroit Diesel 500-horsepower engine with a Jake Brake. How does the engine brake on the Cummins compare to the Jake Brake on the Detroit Diesel?

Thanks,

mike

[wolfe10]

I am presently looking at a motorhome with a Cummins ISX 600 in it.

I have been use to traveling the country in an 18-wheeler over all 48 lower states, on different mountain grades. The 18-wheeler had a Detroit Diesel 500-horsepower engine with a Jake Brake. How does the engine brake on the Cummins compare to the Jake Brake on the Detroit Diesel?

Mike,

Yes, I just called my contact at Cummins. All but the lowest HP ISX's (like under 400 HP) come with an engine compression brake (aka Jake brake). Could a coach manufacturer special order an ISX without an engine compression brake-- YES. In fact, I know that Foretravel orders theirs without the engine compression brake and fits all their coaches with the Allison Transmission Retarder.

The Jake brake on the ISX functions exactly as does the Jake brake on your DD.

Brett Wolfe

[truckr44@yahoo.com]

Brett,

Thanks so much for the reply.

The coach that I am interested in is an Country Coach Affinity. The dealer says that it has an engine brake, but I think that it has the Allison 6000 Transmission. I am not sure about the tranny.

Thanks,

Mike

[wolfe10]

Brett,

Thanks so much for the reply.

The coach that I am interested in is an Country Coach Affinity. The dealer says that it has an engine brake, but I think that it has the Allison 6000 Transmission. I am not sure about the tranny.

Thanks,

Mike

Mike,

I suspect that is the Allison 4000.

Brett

[truckr44@yahoo.com]

Brett,

I have emailed the dealer and waiting on the reply.

As you can tell I am new to the rv forum, and have lots of questions.

You are probably right aboput the Allison 4000.

With the Cummins ISX 600 and the Allison 4000, mountain grades should not be a problem?

Thanks, Mike

[wolfe10]

Brett,

I have emailed the dealer and waiting on the reply.

As you can tell I am new to the rv forum, and have lots of questions.

You are probably right about the Allison 4000.

With the Cummins ISX 600 and the Allison 4000, mountain grades should not be a problem?

Thanks, Mike

Mike.

Power (HP) to weight ratio is a better indicator of climbing ability than just looking at HP along.

For an excellent discussion on coach performance, go to this Caterpillar Corporation document (applies equally well to any engine):

https://ohe.cat.com/cda/files/287140/7/LEGT5364.pdf

Brett Wolfe

[truckr44@yahoo.com]

Brett,

Excellent information.

Thanks,

Mike

[truckr44@yahoo.com]

Brett,

The coach has the allison 4000 6 speed with 2 overdrive gears.

Thanks,

Mike

[wolfe10]

Brett,

The coach has the allison 4000 6 speed with 2 overdrive gears.

Thanks,

Mike

Yup, on all Allison 3000 and 4000 series, 4th is 1:1. 5th is a .75 OD and 6th is .65 OD.

Brett

[cagentile@att.net]

Mike - -

I've got a 45 footer weighing 52,000 lbs. with the ISX 600 hp Cummins and have done a 16 National Parks trip thru the Rockies and a trip to Newfoundland. I found the engine and braking system to perform flawlessly. I had outstanding control in the Rockies on some scary hairpins and downgrades. I towed a GMC pick-up thru the Rockies and the Cummins didn't even breath hard. I am quite satisfied with it's performance. Don't expect to set records for fuel economy however. I average 5.5 mpg.

Hope this helps.

Chris 08, HR Navigator

[truckr44@yahoo.com]

Chris,

Thanks for the reply. That is about the weight I am looking at. Country Coach Affinity, 45 ft, so we will be in the same category. I have not bought the coach yet, hoping to buy in march.

I remember driving trucks in to oregeon on I84, and always dreaded the mountain the truckers called cabbage.

I know that with a 50,000 plus coach, can't expect great mileage.

Thanks,

Mike