Towing a toyhauler in mountains and 85.5 octane

16LT4 · June 28, 2022

Those Western Mountains are a whole 'nuther game compared to Eastern hills. That said, I've noticed a difference even cresting the lowly Catskills in my 442, only 2250ft above sea level. It wasn't the fuel, it was the air. The higher elevation is why less octane is needed than at sea level.

Denver for example, a little higher than Gillette, has air that is 82% as dense as at sea level, humidity being equal. This is where forced induction engines shine, because the intake charge is kept at roughly the same air density by the hair dryer. Because the engine is an air pump, the NA engine is only making ~82% of its power as at sea level, all else being equal. Water boils about a degree lower for every 500 ft of elevation increase. The thinner air at elevation has less ability to absorb heat via the radiator; all of these leads to lower available power to climb the grade, along with more heat and less ability to remove it.

A decade ago, I towed a 4000 lb U-haul trailer 450 miles with my 110 hp '84 GMC S15 with manual transmission. Even mild grades that an unladen vehicle would never notice had me dropping into 3rd and putting the hazards on at 40 mph in a 65 mph. I've always operated on the principal that a trailer combo should be the slowest vehicle on the road; going slower than traffic, no matter how dense, means one will always have a clear lane ahead of them, important when considering increased stopping distances. Slow down, keep it in 3rd or 4th and watch your RPM and fluid temps, not the speedometer. Do 35 mph going up the grade and turn on your hazards if you need to; I've never understood "needing" to keep up with traffic at the expense of abusing the machinery. I'm sure you'd rather make it home, uneventfully, than blow a coolant hose, head gasket, spin a bearing, wipe the marginal torque converter, etc.

mikeyk101 · June 28, 2022

All good info and I will have to remember this the next time I am back out west again. Might not be for some time though.

As far as the tires, they are actually 275/60R20 so that may have come into play as well but I have the speedo corrected by the Rough Country speedo corrector. I believe the speed limit was 65mph but both times especially the second time back through, I was traveling less and no traffic to keep up with. Trans fluid had been changed the first time around 50,000 miles but that will be done again once I get back home.

mikeyk101 · July 2, 2022

I got home safe and sound on Thur afternoon. There was a serious layer of bugs all over the front end, the mirrors, and the front of the toyhauler. I peeked inside the grill and the condenser was pretty caked with bugs as well. I mixed up my go to bug cleaner ( half Hydrogen peroxide and half water) and went to town. I was able to get everything cleaned off pretty well. Then I pulled off the grill to be able to get to the condenser. I used a full can of AC Coil cleaner to spray all over the face of the condenser. I let it sit for several minutes until most of the foam dissipated and then rinsed it real well. It looked much cleaner now. Luckily the fins were still in pretty good shape and only a very tiny percentage needed straightening. Although it will be a while like I mentioned earlier in this thread before I will be back in the mountains, it was still a good idea to do a good cleaning again anyway...

Grumpy Bear · July 3, 2022

8 hours ago, mikeyk101 said:

I got home safe and sound on Thur afternoon. There was a serious layer of bugs all over the front end, the mirrors, and the front of the toyhauler. I peeked inside the grill and the condenser was pretty caked with bugs as well. I mixed up my go to bug cleaner ( half Hydrogen peroxide and half water) and went to town. I was able to get everything cleaned off pretty well. Then I pulled off the grill to be able to get to the condenser. I used a full can of AC Coil cleaner to spray all over the face of the condenser. I let it sit for several minutes until most of the foam dissipated and then rinsed it real well. It looked much cleaner now. Luckily the fins were still in pretty good shape and only a very tiny percentage needed straightening. Although it will be a while like I mentioned earlier in this thread before I will be back in the mountains, it was still a good idea to do a good cleaning again anyway...

Tell me about this product please. Name...where to buy...etc...

mikeyk101 · July 3, 2022

10 hours ago, Grumpy Bear said:

Tell me about this product please. Name...where to buy...etc...

Here is the stuff I used.

AC-Safe Air Conditioner Foaming Coil Cleaner
https://www.homedepot.com/p/AC-Safe-Air-Conditioner-Foaming-Coil-Cleaner-AC-921/206740351
SKU# 206740351

Taking the grill off made it much easier to get access to the condenser. I also "LIGHTLY" used a soft bristle brush across the face of condenser after liberally spraying the cleaner on it to help. The stuff is supposed to be self rinsing but does say you can hose it off afterwards which is what I did. One can was just enough to do the entire face.

I have been also looking for some kind of cleaning wand with a 90⁰ angled sprayer but haven't been really successful. Since bugs and such hit the face and get stuck, I would eventually like to try using a sprayer in between condenser and radiator and try to push the stuff back out the way it got there and really clean out those fins. Removing the top plastic cover and then removing the grill is actually a pretty quick process. I did try to also remove the plastic covering that sits directly on the condenser but wasn't able to detach the tabs that are on either side about a 1/3rd of the way down. That would give access in-between condenser and radiator I believe. At least for now, most of the bugs and such have been taken care off.