RV News RVBusiness 2021 Top 10 RVs of the Year, plus 56 additional debuts and must-see units → ×
RV Trip Planning Discussions

Go Back   iRV2 Forums > iRV2.com COMMUNITY FORUMS > iRV2.com General Discussion
Click Here to Login
Join iRV2 Today

Mission Statement: Supporting thoughtful exchange of knowledge, values and experience among RV enthusiasts.
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on iRV2
Thread Tools Search this Thread Display Modes
Old 07-08-2014, 12:14 AM   #1
Senior Member
Just For Fun's Avatar
Join Date: Feb 2012
Location: Southern California
Posts: 1,447
Driving Differences From Gas to Diesel

If our plans work out, sometimes thay actually do (but rarely in the timeframe intended) we will be selling/trading our gas MH in for a diesel powered coach - probably a Coummins 425 ISL.

I've heard that there is a difference in driving these two different engines - specifically up and down grades.

Anyone out there care to give us a preempted driving lesson?

2006 Monaco Signature 45' Commander IV ISX 600
2013 Avalanche toad
And a rather large and very hairy Bear for a traveling companion
Just For Fun is offline   Reply With Quote
Join the #1 RV Forum Today - It's Totally Free!

iRV2.com RV Community - Are you about to start a new improvement on your RV or need some help with some maintenance? Do you need advice on what products to buy? Or maybe you can give others some advice? No matter where you fit in you'll find that iRV2 is a great community to join. Best of all it's totally FREE!

You are currently viewing our boards as a guest so you have limited access to our community. Please take the time to register and you will gain a lot of great new features including; the ability to participate in discussions, network with other RV owners, see fewer ads, upload photographs, create an RV blog, send private messages and so much, much more!

Old 07-08-2014, 12:40 AM   #2
Senior Member
sknight's Avatar
Appalachian Campers
Join Date: May 2009
Posts: 908
Going from gas to diesel? A Cummins at that?

Set the cruise and let her eat. You'll be amazed at the effortless driving you're about to experience.

They're not the best engine brakes though. Your model might come with an exhaust brake or you can have one installed. If you don't have one just stay on top of your speed going down hills. Downshifted to where my max RPM is around 85% of the engine max I let mine get to the speed limit then use the brakes to pull it about 10-15 below the limit then off the brakes completely to let them cool off. Repeat as necessary. That cooling off period is important, most people just ride the brakes all the way down and lose them when they need them most.

Two things about diesel engines. 1. Don't fire it up and just drive away. Diesels fire off of heat within the cylinder, stone cold they don't have a lot of heat to work with and can have firing issues if worked too hard too quickly. Now, let me be clear, I'm not saying let it idle for an hour, but two to five minutes is all it needs. Plus it will take that long for the air pressure to come up.

2. Don't drop off the highway into the first restaurant you see and shut it off. The turbo needs a few minutes to cool off some and the oil running through it along with low load exhaust cools it off. If you have to drive a couple of minutes to stop then it will be fine, it doesn't need much time, just a little.

I was simply astounded when I switched to diesel power.
2001 HO Cummins powered Dodge 2500
2014 Sierra 346RETS
Nights camped in 2014-28
sknight is offline   Reply With Quote
Old 07-08-2014, 12:54 AM   #3
Senior Member
Skip426's Avatar

Join Date: Apr 2011
Location: Powell River, B.C.
Posts: 21,284
Read up on air brakes & suspension systems there is a lot you need to know. Many states now require air brake training, and some companies will void insurance it you don't have the training you should , check local rules.

425HP, should cure any uphill, problems you think you might have , downhill , ISL, should have a true 2 stage engine brake. Cummins manual will cover the use of this feature. Most owners report the stage 2 is seldom necessary. Stage one provides all the downhill speed control they need. But depends on what you have on behind, trailer / toad.

Took me two hours on the highway to get used to , the change from , my Dodge V-10 with 10,000lb 5er, to my coach.
Safe travels .
99DSDP 3884, Freightliner, XC, CAT 3126B, 300 HP /ALLISON 3060
2000 Caravan toad, Remco & Blue Ox.
Skip426 is offline   Reply With Quote
Old 07-08-2014, 02:20 AM   #4
"Formerly Diplomat Don"
Dutch Star Don's Avatar
Newmar Owners Club
Join Date: Apr 2005
Location: Moorpark, Ca.
Posts: 16,330
Just remember.....gas engines accelerate and diesels gain momentum.

Typically on a hill climb in a gasser, you wring it's neck, if you do that in a diesel, it will fall on it's face.
Don & Mary
2019 Newmar Dutch Star 4018 (Freightliner)
2019 Ford Raptor
Dutch Star Don is online now   Reply With Quote
Old 07-08-2014, 12:36 PM   #5
Senior Member
dvmweb's Avatar
Join Date: Sep 2010
Location: MI
Posts: 1,065
The difference is night and day.

Gasser, modest power, some struggle with any grade if loaded. Brakes are just enough with downshifting. Not the best for very long days on the road.

Diesel, much more power/torque, ride better, exhaust brake, comfortable, more capacities. Glad we upgraded.

2013 FleetWood Expedition 38B
dvmweb is offline   Reply With Quote
Old 07-08-2014, 02:40 PM   #6
Senior Member
djbmsu's Avatar
Join Date: Nov 2011
Location: Polk City Florida
Posts: 1,855
Air Brake Trainning ? never heard of that requirement in any state except perhaps Texas. If you are referring to CDL license then perhaps but I have never heard of any state requireing it for non CDL. If there is a list of states that require it please post it for others.
Don and Nancy
[2017 Tiffin Bus 40 AP, 2018 Jeep Unlimited Sahara JL 6yr old sisters Sara n Kaycee, Havanese, Two Electric Bikes
djbmsu is offline   Reply With Quote
Old 07-08-2014, 03:04 PM   #7
Senior Member
BFlinn181's Avatar
Gulf Streamers Club
Join Date: Jan 2012
Location: Cincinnati
Posts: 19,926
Originally Posted by djbmsu View Post
Air Brake Trainning ? never heard of that requirement in any state except perhaps Texas. If you are referring to CDL license then perhaps but I have never heard of any state requireing it for non CDL. If there is a list of states that require it please post it for others.
It's interesting that many states require an air brake endorsement for commercial drivers and school bus drivers, but not RVers. I got mine 40 years ago for a school bus license. Air brakes and suspension are enough different from autos and pick ups that an RV owner/driver should be educated if their RV is so equipped.

Driving a diesel is different than a gas powered vehicle. Torque comes at much lower RPM and it doesn't do any good to try to rev it to higher RPMS. I've had diesel autos for many years and anyone that tries to drive them has had to change behaviors to get it to behave.

The OP has made a big first step in recognizing there is a difference in gas and diesel vehicles. His learning curve will be accelerated by that recognition.

Bob & Donna
'98 Gulf Stream Sun Voyager DP being pushed by a '00 Beetle TDI
BFlinn181 is offline   Reply With Quote
Old 07-08-2014, 11:31 PM   #8
Senior Member
dons2346's Avatar
Country Coach Owners Club
Join Date: Dec 2010
Posts: 6,238
Originally Posted by Dutch Star Don View Post
Just remember.....gas engines accelerate and diesels gain momentum.

Typically on a hill climb in a gasser, you wring it's neck, if you do that in a diesel, it will fall on it's face.

Yup, this about sums it up.

Oh, and by the way, the modern diesel motor will have either an exhaust brake or the engine brake which is better known as a "jake" . ither will get you down the hill safely, you just have to learn the limits of each and how to use them.

There is also the transmission retarder but the only coach other than bus conversions that has it is the Foretravel
dons2346 is offline   Reply With Quote
Old 07-08-2014, 11:45 PM   #9
Registered User
Fleetwood Owners Club
Freightliner Owners Club
Join Date: May 2011
Location: Silicon Valley, CA
Posts: 1,857
According to Allison

According to Allison the transmission in my Bounder has a transmission retarder that works in conjunction with the exhaust brake.

Going down grades is no longer terrifying like it was in our gasser. Going up grades is no longer a problem either.

Better suspension. Higher carrying capacity. Better fuel mileage. What 'a not to like?
Muddypaws is offline   Reply With Quote
Old 07-09-2014, 05:01 PM   #10
Senior Member
xctraveler's Avatar
Tiffin Owners Club
Freightliner Owners Club
Join Date: Jun 2004
Location: Aguanga CA Jojoba Hills SKP Resort
Posts: 346
Recently, a couple of years ago, we changed our drivers licenses from NY to TX. Although we read about and answered some questions on air brake systems, on the road test the examiner did not put us through the air system departure check required for full CDL. In fact our backing test was from a straightaway stop back up in a straight line for 50 feet.

So we do NOT have an air brake endorsement even for a coach well over 26k lbs gvwr and it apparently is not required in TX either.
Paul Rocking down the road in our '12 Phaeton 36QSH, (in service May 2012 ) We tow an '11 4 dr Jeep Wrangler Unlimited Rubicon - Read my blog at goldberg-online.net AKA RVM86
xctraveler is offline   Reply With Quote

diesel, gas

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
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

Similar Threads
Thread Thread Starter Forum Replies Last Post
Looking for diesel fuel jillie Class B Motorhome Discussions 14 05-16-2014 08:55 AM
Driving Lessons OWV Jayco Owner's Forum 7 02-07-2014 05:52 AM
Replacing Gas Engine with Duramax Diesel and Allison Transmission? Ed Anderson MH-General Discussions & Problems 15 10-31-2013 05:45 PM
Thor Gas Club rvbunz Thor Industries Owner's Forum 24 09-14-2013 07:00 PM
Diesel vs Gas? malexander Class A Motorhome Discussions 40 08-25-2013 06:55 PM

All times are GMT -6. The time now is 07:42 PM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.