Climbing steep grades...

We just finished a Yellowstone run towing our Honda van. Coolant temps averaged 195F, running up to 208F on extended uphill grades. Temps via DashCommand and our OBD2 wifi reader...

FunTwoDrv wrote:
Okay, I40 at Black MT is a 5 mile 6% grade. I run in the right lane and pretty much stay with the trucks and some other RV's. Of course we hit it at 60 or so and then down to 45mph for most of the way. I do let it trail off the last half mile or so just because I don't like to push it as long as I'm not impeding traffic. So, I don't attempt to run up it, or any other long grade, at full throttle. We'm about 18.6k lbs so, below our GCWR of 20K.
No heating problems thus far and we've been from NC to WA and everywhere in between.
Cheers,
Gary

Ok that makes more sense, you are choosing to back off the throttle. 45 mph on a 6% grade at that weight sounds about right.

If 25 mph is the best you can do on a 6% grade, that is pretty good evidence you are carrying too much weight.

5000 feet is nothing. My house is higher than that. Fuel injection is a huge improvement compared to the old carburetors and vapor lock problems.

Stay out of Canada if you have difficulty with 6 % grades. They have main highways with 11-12% grades.

Okay, I40 at Black MT is a 5 mile 6% grade. I run in the right lane and pretty much stay with the trucks and some other RV's. Of course we hit it at 60 or so and then down to 45mph for most of the way. I do let it trail off the last half mile or so just because I don't like to push it as long as I'm not impeding traffic. So, I don't attempt to run up it, or any other long grade, at full throttle. We'm about 18.6k lbs so, below our GCWR of 20K.
No heating problems thus far and we've been from NC to WA and everywhere in between.
Cheers,
Gary

"HUH??? Have you driven I-17 from Phoenix to Flagstaff or Flagstaff to Phoenix??? I've been down to 15mph or lower behind heavy trucks when passing was impossible on that route. If you can live with the reduced speed on a hard climb and your engine and transmission is not overheating, and you're running within weight limits, YOU ARE NOT OVERLOADED AND YOUR TOAD IS JUST FINE. You do not have to fly up steep hills at 70mph.

Frankly, someone having fun following me up a steep hill does not concern me at all. I will be in the right lane, obeying the local and state laws. and if my speed bothers you, go around. My job is not to keep someone behind me having fun."



I have driven those routes dozens of times and have NEVER seen anyone down to 15 mph. I do see trucks chugging along at 35 with their flashers on and yes passing them is a PITA. Driving far slower than the flow of traffic is not only dangerous, rude and foolish it is also illegal. No one said you have to "fly up steep hills at 70".

If you are going 15 - 25 you are not obeying the local and state laws or the feds for that matter and the interstates are their jurisdiction. I stand by my opinion that if you are only able to do 25 mph on a 6 percent grade something is wrong. You are correct that your job is not to keep someone behind you having fun...Your job is to drive safely. Sorry you don 't get that.

As always... opinions and YMMV.

:R

FunTwoDrv wrote:
For reference, we pull a 4500# Wrangler with a 6.0, 6sp, 32' C. running up Black Mountain on I40, our temp creeps up as you mentioned. I run with the "Tow/Haul" mode turned on and the trans does it's thing with downshifting. We are around 25mph when we reach the top. The Scangage shows water temp a touch lower than the instrument cluster by 5 or so degrees. I added another external trans cooler to aid in controlling those temperatures as we travel the Rockies as well with this setup.
Gary

I would wonder if you were running full throttle (or were able to) with those slow speeds on a 5-6% grade. I used to have an older, less powerful (just 265 hp) Ford E450 running about 1500 less GCW than your rig, and I could maintain a solid 45 mph on a 6% grade regardless of outside temperatures. I could run said 6% grade in high-90 degree temperatures at full throttle without overheating. If you are forced to back off the throttle to avoid overheating I would submit that you have issues with your cooling system. Then again, it could be just the drivetrain, my 2005 Chevy 2500HD would heat up when pulling hard in hot weather.

Desert Captain wrote:
"We are around 25mph when we reach the top."

IMHO:

If the best you can do on a 6 percent grade on the interstate is 25 mph you have waaaay too much Toad and/or not nearly enough power for the load you are expecting it to haul.
Even heavily loaded 18 wheelers do better than that.

Class C's over 30' tend to have very little payload available and adding a Toad that is very close to your max towing capability is a recipe for disaster. You may be FunTwoDrv but probably are not much fun to follow.

As always... Opinions and YMMV.

:E

HUH??? Have you driven I-17 from Phoenix to Flagstaff or Flagstaff to Phoenix??? I've been down to 15mph or lower behind heavy trucks when passing was impossible on that route. If you can live with the reduced speed on a hard climb and your engine and transmission is not overheating, and you're running within weight limits, YOU ARE NOT OVERLOADED AND YOUR TOAD IS JUST FINE. You do not have to fly up steep hills at 70mph.

Frankly, someone having fun following me up a steep hill does not concern me at all. I will be in the right lane, obeying the local and state laws. and if my speed bothers you, go around. My job is not to keep someone behind me having fun.

Have you weighed your Class C and Jeep? Are you sure you're not over weight?

"We are around 25mph when we reach the top."

IMHO:

If the best you can do on a 6 percent grade on the interstate is 25 mph you have waaaay too much Toad and/or not nearly enough power for the load you are expecting it to haul.
Even heavily loaded 18 wheelers do better than that.

Class C's over 30' tend to have very little payload available and adding a Toad that is very close to your max towing capability is a recipe for disaster. You may be FunTwoDrv but probably are not much fun to follow.

As always... Opinions and YMMV.

:E

For reference, we pull a 4500# Wrangler with a 6.0, 6sp, 32' C. running up Black Mountain on I40, our temp creeps up as you mentioned. I run with the "Tow/Haul" mode turned on and the trans does it's thing with downshifting. We are around 25mph when we reach the top. The Scangage shows water temp a touch lower than the instrument cluster by 5 or so degrees. I added another external trans cooler to aid in controlling those temperatures as we travel the Rockies as well with this setup.
Gary