Long distance Towing questions (New Lifters too)

MikeMSierra · May 23, 2022

Hello,

I plan on towing a car 1,000mi (each way) with my 2020 GMC sierra 5.3, 10sp tranny. Car (Mini Cooper) + trailer weight = 5,000 lb, truck listed as 9,400 lb max.

Manual said to let the truck idle before shutting off during long hauls, etc. was wondering if you folks have any other recommendations.

My first truck and first time towing. All lifters replaced at 5,800mi (2 months ago), currently have 6,700 mi.

Thanks

MrStick · May 23, 2022

Letting it idle may help with cooling your transmission down some. I haul maybe 300 miles one way and really do not let my trucks idle when I arrive at my destination.

swathdiver · May 23, 2022

I've been idling down whatever was driven for near forty years. Think nothing of making that run.

Gangly · May 23, 2022

If it says to idle down, then its probably best to idle down. I would keep an eye on transmission temperatures to make sure they don't go too high, but if its running 190 degrees or cooler I wouldn't bother with the idle down process.

RetCPO · May 25, 2022

I just got back last Fri towed 1800 mi round trip in my 5.3 2020 AT4 towed 3500 lb trailer down 900 mi. empty and loaded up a 3700 lb. mustang and towed back. I'm guessing you have a tow package on your truck, when you twist the dial to the trailer icon on your dash a transmission temp gauge will pop up on your gauge display. I had no issues with engine temp or trans temp, engine temp stayed right in the middle and trans never went above 185 degrees and it was 85-95 degrees outside for a good portion of the trip. Your not going to have any problem towing 5000 lbs. Have a safe trip.

Gangly · May 25, 2022

10 hours ago, RetCPO said:

I just got back last Fri towed 1800 mi round trip in my 5.3 2020 AT4 towed 3500 lb trailer down 900 mi. empty and loaded up a 3700 lb. mustang and towed back. I'm guessing you have a tow package on your truck, when you twist the dial to the trailer icon on your dash a transmission temp gauge will pop up on your gauge display. I had no issues with engine temp or trans temp, engine temp stayed right in the middle and trans never went above 185 degrees and it was 85-95 degrees outside for a good portion of the trip. Your not going to have any problem towing 5000 lbs. Have a safe trip.

Great report and info, thanks!

diyer2 · May 25, 2022

So your traveling on the freeway in your car or towing with a truck and you pull into a rest area. If you shut it off without and idle down the temperature will go up I believe. Seems to me this is what I remember when I had a mechanical temp gauge.

I don't shut if off, we take turns using the rest room, one waits in the vehicle. If I were alone, definitely idle down to cool it off.

YMMV

Edited May 25, 2022 by diyer2

KARNUT · May 25, 2022

Well damn! Another thing (they) say you should do I didn’t. With everything temperature controlled as long as everything was normal I shut it down. Of course I believe that synthetic oils could handle extreme heat. Never had reason to doubt what (they) said. Usually when I stopped at a rest area time was essential.

StinkyCheese · May 25, 2022

Only time I let anything cool down is if I've been running it hard. So I'll leave it running with the keys in it while I use the rest stop if we're traveling in a group. Alone I'll shut it off or use auto start and go do whatever I need to do. I've never really towed what would be considered heavy though (10k is about the max for me other than the boat which weighs more). Just watch your gauges and temps. Don't try to win any races, stick to the right lane and let everyone be in a hurry. Does the manual say anything about what temps to let it cool down or just a general statement of letting it cool down. If you're fine with letting it idle and the fuel consumption then let it idle for a few.

Other things you should check would be the same for any road trip. Tire pressure, oil levels, as well as other fluids, if you're one to change a tire yourself instead of calling AAA then make sure you have the equipment for that. Couple of boards to drive up/back up on if the trailer is a double axle so you can easily change a tire if need be. Gloves, some type of triangles or flashing "triangles" are always good to have in the vehicle normally. CHECK YOUR SPARE(S). I don't know how many times I've gone to help some rando or friend on the side of the road and their spare was flat. If I didn't have an onboard air system then that would have been super annoying.

Gangly · May 25, 2022

30 minutes ago, Chevyguy85 said:

Only time I let anything cool down is if I've been running it hard. So I'll leave it running with the keys in it while I use the rest stop if we're traveling in a group. Alone I'll shut it off or use auto start and go do whatever I need to do. I've never really towed what would be considered heavy though (10k is about the max for me other than the boat which weighs more). Just watch your gauges and temps. Don't try to win any races, stick to the right lane and let everyone be in a hurry. Does the manual say anything about what temps to let it cool down or just a general statement of letting it cool down. If you're fine with letting it idle and the fuel consumption then let it idle for a few.

Other things you should check would be the same for any road trip. Tire pressure, oil levels, as well as other fluids, if you're one to change a tire yourself instead of calling AAA then make sure you have the equipment for that. Couple of boards to drive up/back up on if the trailer is a double axle so you can easily change a tire if need be. Gloves, some type of triangles or flashing "triangles" are always good to have in the vehicle normally. CHECK YOUR SPARE(S). I don't know how many times I've gone to help some rando or friend on the side of the road and their spare was flat. If I didn't have an onboard air system then that would have been super annoying.

Onboard air is the way to go. I keep a Viair system in the truck and bring along a Milwaukee M12 compressor for long trips as well.

pokismoki · May 26, 2022

why tow a heavy trailer? is it manual or auto in the cooper? to save weight and load on the truck I would use a car dolly, or if a manual car , tow as is no trailer needed.

175 thermostat and a trans stat delete on my truck and I pull a 6000lbs trailer 300 miles a day when camping, never needed to idle down before, my trans temp is 148, and engine is a steady 185-190

Edited May 26, 2022 by pokismoki

kmeleon · May 27, 2022

Just pulled my 18 camaro SS 1LE (3650) in my new 24ft enclosed trailer (4300lbs) about 120 miles each way to the race track yesterday in my 21 Elevation 5.3 10spd. Tried to stay between 65-70mph on the 70mph highways and mostly in the right lane (10.3mpg). Occasionally I'd have to pass a truck that was just running too slow but the key is, don't be in a hurry (still learning that). Trans maybe hit 175F in 75 degree ambient temps. Truck pulls it pretty damn well, truck is rated for 9300lbs.

Oh FYI, I use a Blue Ox weight distribution hitch. Definetely need one of those pulling this trailer.

Edited May 27, 2022 by kmeleon

diyer2 · May 27, 2022

It's a simple thing.

Give me a good reason no to do an idle down. Oh shoot, that was the wrong thing to say there will be some dumb replies I'm sure.

Grumpy Bear · May 27, 2022

Exhaust valve temperatures under greater than average load will get pretty toasty. Idle down for a few minutes will cool them by hundreds of degrees. Longer valve life. Tis the old school rule.

Idling will not cool the transmission. No air through the system and pump volume at idle is near nil. In my truck it will actually heat up until the fans kick in which is much higher than it runs normally.

customboss · May 27, 2022

2 minutes ago, Grumpy Bear said:

Exhaust valve temperatures under greater than average load will get pretty toasty. Idle down for a few minutes will cool them by hundreds of degrees. Longer valve life. Tis the old school rule.

Idling will not cool the transmission. No air through the system and pump volume at idle is near nil. In my truck it will actually heat up until the fans kick in which is much higher than it runs normally.

Not heat soaking turbo bearings too a good reason to allow a cool down and stabilization of temps so oil doesn't coke there.