I believe there's a Mac in my future, probably a few years off yet, but I am already trying to plan for things such as towing. I hate to keep bringing up the same question as everyone else (can I tow a mac with my...), but this will be my first boat towing experience, and know nothing about any of it.
I am driving an '05 Chevy Colorado Z71 LS extended cab with the I-5 engine. It's a manual transmission. I know that towing with a manual is not optimal, and that I'll have to run higher RPMs than normal, etc. However, since it's basically brand new, I hate to have to replace it in a few years for a bigger tow vehicle. From what I read here, I'm guessing it will be possible to tow the Mac around town without too much trouble, but I'd like to be able to tow it FAR in order to use it in the Keys, Gulf, etc.
Obviously, bigger is usually better, and safety is relative, but would YOU do it? How about around town or on shorter trips (several hundred miles instead of over a thousand)?
I appreciate any advice any of you can give me. Thanks in advance.
I hate to beat a dead horse, but...
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jklightner
- Engineer
- Posts: 142
- Joined: Fri Jul 09, 2004 1:49 pm
- Location: Tacoma, WA
The wheelbase of the extended cab Colorado, is, what I'd consider, only a bit short for a Mac at 126", but it's better than what many who tow a Mac have. Because of this, I'd keep towing speed a little lower than I would with a longer wheelbase truck.
The biggest problem frequently found with manual transmissions on light trucks is that they sometimes use a smaller clutch. Automatics have a fluid torque converter to allow the drivetrain to slip whille taking off under load, and the heat created from that slippage is carried away and dissapated through a cooling system. That's not the case with the clutch, and the smaller it, and the flywheel's size, the less the heat that can be dissapated. The heavier the load, the greater the slippage, and thus heat, when starting out and shifting.
Only so much total weight can be pulled to a start frequently, for many reasons, not only including drivetrain strength and wear, but chassis strength as well. The larger the truck (i.e. cab) and greater its weight, the less the trailer can weigh to keep the total weight pulled by the drivetrain the same. You can see that with some of the different Colorado cabs. The greater the truck weight because of options, especially 4WD, the less the trailer can weigh to keep the total weight pulled by the drivetrain the same. Horsepower and gear ratios also play a role in determining the maximum total weight that can be towed.
The I-5 Automatic can tow 4,000 lbs regardless of cab or 2WD vs 4WD. That tells me the drivetrain with the automatic isn't the limiting factor. Perhaps its the strength of the frame or the axle limits. However, when you look at the I-5 Manual, you can see the best tow capacity is 3800 lbs, and goes down 100 lbs with the additional weight of the Extended Cab, and goes down 300 lbs with the additional weight of the 4WD system.
You'll also notice that the Gross Vehicle Weight Rating of the Extended Cab Z71 Colorado is 5300 lbs with either 2 or 4WD, and with the 4WD and near 300 lb additional curb weight, its "payload" (fuel, people, cargo, and tongue weight) is near 300 lb less the 2WD version.
You don't say whether your truck is 2WD or 4WD, but that would put its towing capacity at 3700 or 3400 lbs respectively. That must be reduced by the weight of a full tank of fuel, any passengers other than the driver, and any cargo in the truck. These things, as well as the weight of the driver and the trailer tongue, must come out of the "payload".
The result of towing a 4,000+ lb MacGregor rig, in excess of this truck's rating, is probably just going to be higher wear and tear, and sooner replacement of parts, particularly the clutch, and given the limit of the automatics, possibly a little more wear on the axle ring(s) and pinion(s). You can minimize that by concentrating on taking off with as little throttle, and as little clutch slippage (i.e. get the pedal full out as quickly as possible), as possible. As long as you keep the speed on the highway moderate, I don't think safety would be a problem.
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Moe
The biggest problem frequently found with manual transmissions on light trucks is that they sometimes use a smaller clutch. Automatics have a fluid torque converter to allow the drivetrain to slip whille taking off under load, and the heat created from that slippage is carried away and dissapated through a cooling system. That's not the case with the clutch, and the smaller it, and the flywheel's size, the less the heat that can be dissapated. The heavier the load, the greater the slippage, and thus heat, when starting out and shifting.
Only so much total weight can be pulled to a start frequently, for many reasons, not only including drivetrain strength and wear, but chassis strength as well. The larger the truck (i.e. cab) and greater its weight, the less the trailer can weigh to keep the total weight pulled by the drivetrain the same. You can see that with some of the different Colorado cabs. The greater the truck weight because of options, especially 4WD, the less the trailer can weigh to keep the total weight pulled by the drivetrain the same. Horsepower and gear ratios also play a role in determining the maximum total weight that can be towed.
The I-5 Automatic can tow 4,000 lbs regardless of cab or 2WD vs 4WD. That tells me the drivetrain with the automatic isn't the limiting factor. Perhaps its the strength of the frame or the axle limits. However, when you look at the I-5 Manual, you can see the best tow capacity is 3800 lbs, and goes down 100 lbs with the additional weight of the Extended Cab, and goes down 300 lbs with the additional weight of the 4WD system.
You'll also notice that the Gross Vehicle Weight Rating of the Extended Cab Z71 Colorado is 5300 lbs with either 2 or 4WD, and with the 4WD and near 300 lb additional curb weight, its "payload" (fuel, people, cargo, and tongue weight) is near 300 lb less the 2WD version.
You don't say whether your truck is 2WD or 4WD, but that would put its towing capacity at 3700 or 3400 lbs respectively. That must be reduced by the weight of a full tank of fuel, any passengers other than the driver, and any cargo in the truck. These things, as well as the weight of the driver and the trailer tongue, must come out of the "payload".
The result of towing a 4,000+ lb MacGregor rig, in excess of this truck's rating, is probably just going to be higher wear and tear, and sooner replacement of parts, particularly the clutch, and given the limit of the automatics, possibly a little more wear on the axle ring(s) and pinion(s). You can minimize that by concentrating on taking off with as little throttle, and as little clutch slippage (i.e. get the pedal full out as quickly as possible), as possible. As long as you keep the speed on the highway moderate, I don't think safety would be a problem.
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Moe