Community Forums

Skip426 · 05-24-2020, 11:24 AM

With the Allison mode button on Economy , shift into 6th gear is at 58 MPH , 1650 RPM , I usually set cruise for 1750 , to keep the trans from hunting ( 5th/6th shifting) on rolling terrain . These numbers will vary coach to coach .

Here's the Cat info mentioned , and it's Cummins equivalent.

Ray,IN · 05-24-2020, 08:47 PM

When planning driving time for a trip, I always use 50 MPH average. Including rest stops, lunch stop, fuel stop, my daily driving distance closely matches my 50MPH planning estimate. My actual driving speed is 63-65 MPH on interstates.
I only monitor fuel mileage to keep an eye on normal engine performance.

awol50 · 05-24-2020, 09:02 PM

55-65 depending on traffic, roads and weather. Pulling toad computer says 10 mpg or so. I think it is off by 10% so really 9 mpg or so. 6.7 isb. 38'.

On a typical road day of 8 hours drive time I add 40 minutes for driving slower. Way less stressful, tiring and safer.

jrj89134 · 05-24-2020, 09:07 PM

Thanks guys that’s about what I thought.

Mr_D · 05-24-2020, 09:12 PM

62 to 65 is a good speed for me. But I use 55 mph for figuring time on the road.

scubadude62 · 05-24-2020, 10:17 PM

I set my cruise at 60 (65 where the limit is 75 or higher). For planning purposes, I use an average of 50mph when planning arrival times. Don't forget the time zone changes!

JFXG · 05-25-2020, 01:39 AM

Jen... First of all, WELCOME to iRV2!! You’re in the right place!

Now, 8 yrs and 48K miles of fulltiming, I always set my cruise for 1750 (CAT 3126) Why? Because it’s halfway between the MAX TORQUE and MAX HP. This has me cruising about 63-65.
I don’t plan a particular average speed, although I guess it works out to about 50. We travel for the most part without daily reservations, unless it’s a specific holiday time or a very popular destination. We travel about 200 to 250 miles/day, which takes about 5 hours counting a lunch stop. Two days of travel, then a day off. Our travel rule of thumb for gross estimates in advance is about 150 miles per day.

JFXG

Dav L · 05-25-2020, 07:45 AM

I don't know where the folks that state they drive that far below the speed limit are because when I am on the road, I find the RVs are going pretty close to the speed limit with exception of long hill climbs. No matter the road. What hurts an RV's average speed is negotiation with traffic. No weaving across lanes in an RV to get around the slowest on the road, who are typically (hopefully) in the right lane where most of the RVs run.

I also am almost the speed limit. Exception is the few over 70mph highways that are starting to appear. I limit myself to under 70.

I am sure you have been driving a few year (car)....what speed are you seeing the RVs drive?

Unicorn Driver · 05-25-2020, 04:08 PM

Quote:

Originally Posted by Dav L

I don't know where the folks that state they drive that far below the speed limit are because when I am on the road, I find the RVs are going pretty close to the speed limit with exception of long hill climbs. No matter the road. What hurts an RV's average speed is negotiation with traffic. No weaving across lanes in an RV to get around the slowest on the road, who are typically (hopefully) in the right lane where most of the RVs run.

I also am almost the speed limit. Exception is the few over 70mph highways that are starting to appear. I limit myself to under 70.

I am sure you have been driving a few year (car)....what speed are you seeing the RVs drive?

Most motorhomes in lower Michigan I see going 60-65. Travel trailers generally about the same. Its the 5th wheels i see really belting along.

Bham · 05-25-2020, 06:47 PM

My Showhauler/Volvo (Bismarck) likes to cruise between 65 and 75 mph. I tend to fall in behind a big rig and motor calmly along. If I’m going on a long haul ( eg Toronto to Vegas) I like to start driving about 8:00 and finish up somewhere around 7:00. I usually stop twice a day plus bio breaks. She handles like a dream and seldom notices trucks or windy conditions. I love to drive a nice sports car, and my Bismarck is one big solid super sports truck.

F4Gary · 05-25-2020, 07:41 PM

What RV are you driving?

Rodg495 · 05-25-2020, 07:48 PM

Quote:

Originally Posted by n2zon

Internet speed? Roughly 186,000 mph! ;-)

But you probably meant interstate highway speed. I'm usually near the speed limit on the road. Mileage varies as a rough function of the square of the speed, IIRC (always a dangerous assumption!).

I think that, pretty much by definition, the torque peak is the engine's most efficient RPM. For hill climbing that plays well to the diesel engine's low torque and power peaks, but for gas you wind up at much higher RPM to get enough power, which is not a particularly efficient place to be. You (well, I) likely do not care much about that in a gasser because you'd like to top that hill some time this week. In either case you will probably want to be at or near the power peak, though. For my Cummins ISL, that's 2000-2100 RPM. For the old Winnie it was something closer to 5000-5500 RPM.

That's a bit slow for internet speed... it's more like 186,000 miles per SECOND.

grindstone01 · 05-25-2020, 07:59 PM

Drive the speed you are comfortable driving at! If after 2 hours, you discover your shoulders are sore and you feel uptight, then you may be driving too fast. Driving is suppose to be fun and a big part of any trip. Look for the drivers sweet spot, the vehicle's computer will figure out the mechanics.

tommar · 05-25-2020, 08:30 PM

I don't worry about average speed. I'll get there when I get there; I'm not on a business trip in my MH! But MPH is a whole nother thing. On some 2-lane roads, I may only go 45 if it's a really bad, crowned road with lots of patches on it. Other roads, I can push 60. On the Interstates, for the most part around 60-65. My rig seems to like about 1700-1750 rpm. I use the Allison economy mode. I've never towed a toad so I dunno if economy would be OK to use. Never driven in the mountains (I live in Texas where it's flat!) but the tranny seldom hunts gears.