How to figure out if my tow vehicle has enough power?

[Krabi Sunset]

I just bought a Chaparral 310 Signature. She weights 10,600 lbs dry.

I currently drive a 2005 BMW 730: Power is supplied by a double overhead camshaft, 3 litre/liter naturally aspirated 6 cylinder engine, with 4 valves per cylinder that develops power and torque figures of 254.5 bhp (258 PS/190 kW) at 6600 rpm and 300 N·m (221 lb·ft/30.6 kgm) at 2500-4000 rpm respectively.

A 6 speed automatic transmission transfers the power to the rear wheels.

It's claimed weight (car) at the kerb is 4045 lbs.

I am not in the USA, so I do not have to follow any laws about the width of the tow vehicle vs. the trailer/boat. All I need to know is will I be able to tow that much weight with the motor I have?

[john61ct]

In practice no, you'll wreck the car. Transmission getting too hot, way overloading the whole drivetrain, not to mention brakes and rear suspension.

Get a decent heavy V8 pickup, or ideally a diesel, especially if there are any hills.

Look at what commercial trucks are using, delivering beverages for example. In the US a 3/4 to 1-ton, aka 350/3500 minimum. Diff and tranny ratios specific for towing as well, not fuel efficiency.

4WD best if doing any ramp launching.

[panglaodave]

Originally Posted by Krabi Sunset

I just bought a Chaparral 310 Signature. She weights 10,600 lbs dry.

I currently drive a 2005 BMW 730: Power is supplied by a double overhead camshaft, 3 litre/liter naturally aspirated 6 cylinder engine, with 4 valves per cylinder that develops power and torque figures of 254.5 bhp (258 PS/190 kW) at 6600 rpm and 300 N·m (221 lb·ft/30.6 kgm) at 2500-4000 rpm respectively.

A 6 speed automatic transmission transfers the power to the rear wheels.

It's claimed weight (car) at the kerb is 4045 lbs.

I am not in the USA, so I do not have to follow any laws about the width of the tow vehicle vs. the trailer/boat. All I need to know is will I be able to tow that much weight with the motor I have?

Don't do it! 730 towing capcity is only about 4000-4600lbs
Towing CapacityÂ*BMWÂ*730

[Ex-Calif]

Take a look at this...

http://axleadvisor.com/towing-capacity/

In Thailand your best shot may be to locate a V8 Nissan Titan or Toyota Tundra...

[tworail]

You will want at least a 3/4 ton pickup with a diesel engine... Add in the trailer weight of 2-3k pounds and you are even at the 'safe' upper range of my F250's towing capacity.

Call a professional if you want this moved. Can't even see how you would be able to get the proper sized hitch mounted on the BMW. The tongue weight would probably put the front wheels in the air! Would make a great Youtube video though.

[Sailmonkey]

It’s not the engine that limits you.

It’s the gearing. Your car is designed to move itself and people, with a little reserve left over for light towing.

Another huge problem is the mass. The boat EMPTY weighs more than twice what the car does. What do you think will happen when you turn? Going slowly....not much, but at greater speed, the boat will control the car. Not ideal.

If you’re not going to move it very often by trailer, contract the move to someone with an appropriate vehicle.

If it’ll be on the trailer on a regular basis, get an appropriate tow vehicle for that size of load.

[keepondancin]

There should be a sticker somewhere on the vehicle, or info in the owners manual, or go on line with BMW, and it will give you towing limits. It is determined by suspension, gearing, engineered strength and driveline limitations. That is the diffinitive answer.

[MarkSF]

A typical hitch for that car would be a class 1, rated for 2,000 lb. Most hitches for unibody cars are class 1, because there's only so much force you can apply when the hitch is mounted to a unibody. Any more, things start to bend. Hitches for higher loads are usually bolted straight to a chassis, on body-on-chassis vehicles.

[kendalk]

You might want to look at the following link:
Towing CapacityÂ*BMWÂ*730d

It shows that the maximum towing capacity for the BMW 730 (2005 - 2015) is 2100KG (4629#).

With that info, it is quite apparent that the suspension will quickly get destroyed, the transmission will quickly get destroyed, and quite likely the engine will also get destroyed.

The only thing the BMW will be good for is a boat anchor.

This size boat (and trailer) needs to be towed with a truck - not a car.

[Brewgyver]

Never mind destroying the car, that combination is just plain UNSAFE. If you were involved in an accident, you could be held criminally negligent.

[lensming]

Absolutely not. You'll destroy the BMW and/or kill yourself and potentially, other people.

Listen to what some of the other posters are saying about a full-size, 3/4 or 1 ton truck.

[Cheechako]

Your problem isnt HP or Torque. It's the frame and weight of the tow vehicle. The boat will be driving the vehicle.

[Mango51]

No. Buy a Mercedes unimog there very cheap and can tow a 747.

[oleman]

You are basically in a situation where your present vehicle would not be safe to move your vessel. Unless you are going to keep the vessel on the hard and transport it to every launch you will be better off if you hire a professional to move the vessel for you. We own a heavy vehicle with large towing capacity it is (old but is well maintained) to be safe to tow BUT the cost of ownership is too large to be justified. It is also not a practical vehicle for everyday use so I also have a Nissan Versa, more cost just to live on land.
Old sailor once told me a boat should be small enough to fit on top of a vehicle or large enough to live on.

[Montanan]

Frankly, the small Beemer has no chance, it would be dangerously hard pressed to tow even a MacGregor day sailer. Given the boat and trailer and some load onboard you are looking at say 14,000+ pounds, which probably greater than 3 times the weight of the car and the boat has a ten foot beam which means a wide trailer whereas the car is only 6 feet 3 inches wide. Keep things in perspective that boat has 600 horsepower. You would need ridiculously extra long side mirror extensions mounted on the BMW to be able to view backwards. The Beemer torque is inadequate especially at low rpm when it is needed to pull up a ramp.

Consider a Ford 250HD [albeit a bit light for your challenge, not sure if a 250 comes in dually wheel rear axle], a 350Superduty or even a 450 Superduty, or a Chevy / GM 3500. Possibly a RAM 2500, if you don't have hills to contend with. You should have four wheel drive to handle ramps, two wheel drive will just spin and slip when trying to remove your so called "Floating Resort" from the water. I would seriously consider a fifth wheel trailer and truck for stability and mid vehicle tongue loading. Typical dual wheel rear axle pickup trucks can handle that trailer capacity with added traction and stability. Dual wheels are a PITA as to parking with their extra wide flair rear, but they can carry a heavy load and provide great stability and traction. If anything you want a vehicle with somewhat over capacity, not undercapacity, or just barely having the rated capacity.

Nissan's 2018 Titan XD is only rated to 11,280 even with its large Cummins diesel engine, so that rig will not cut it. You really need one of the heavier duty American rigs.

Better yet just contract the hauling to someone that is a professional, much less expensive than ownership of the rig you require. The Chapparrel is really pushing the limits of reasonable trailerability.

Useful reference on vehicle options: https://www.cheatsheet.com/automobil...tml/?a=viewall