Teach me about towing

"Flynorcal: pilot, offshore sailor, car racer and panty thief" (flynorcal)
03/03/2018 at 03:32 • Filed to: None

I’m somewhat ignorant about towing a car on a trailer. I see lots of big trucks towing things but don’t understand the formula. I get the concept on tongue weight affecting your suspension and torque to get things rolling but what about this as a tow vehicle:

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I’m looking to step up to racing with NASA and the car won’t be legal for the street. I don’t care to own a truck. I do greatly want to own that wagon.

Would that haul a Corvette on a trailer up a hill at 55 mph or am I wildly misguided? Is it possible to own a tow vehicle that is badass all on it’s own? Because I’m all about that wagon if it’ll do the job.

DISCUSSION (19)

Twingo Tamer - About to descend into project car hell. > Flynorcal: pilot, offshore sailor, car racer and panty thief
03/03/2018 at 03:59

Those apparently have a 2000kg tow rating so it depends how heavy the Vette plus trailer is.

Flynorcal: pilot, offshore sailor, car racer and panty thief > Twingo Tamer - About to descend into project car hell.
03/03/2018 at 04:06

That doesn’t sound like a lot but how is such a rating figured? Is that the total amount of car + trailer weight? How is that number derived and where did you look it up? The car is more than 2000kg so if I try to tow it with the wagon what goes wrong?

Sorry if I sound daft but I’m completely serious. I’m totally ignorant of the subject.

BvdV - The Dutch Engineer > Flynorcal: pilot, offshore sailor, car racer and panty thief
03/03/2018 at 04:09

It would be fine under European towing conditions (trailer with brakes, and a low-ish tongue weight (like 50-100kg) , speed limited to 55/60 mph). The problem is that you guys load differently, higher tongue weights if I’m not mistaken, due to trailer wheels generally being further back, which these cars aren’t designed to handle, or at least not up to the payload you’d need to transport a car.

In Europe it is very common to see a car of this size (or smaller) towing a trailer with a car on it, so it should be doable from the torque perspective.

Twingo Tamer - About to descend into project car hell. > Flynorcal: pilot, offshore sailor, car racer and panty thief
03/03/2018 at 04:09

Hammerhead Fistpunch did some pretty good posts on the details that explain it a lot better than i could. I’ll see if I can find them.

CRider > Flynorcal: pilot, offshore sailor, car racer and panty thief
03/03/2018 at 04:13

The 540i has no official towing capacity. If you are going to install a hitch, your GCWR - curb weight is the max you can tow. Hitch weight shouldn’t really exceed ~10% of trailer weight, and that has to be less than your payload rating. Having the power to tow isn’t really a problem, you will run into more problems overheating your engine and transmission going up hill (this is why trucks have massive grills- it isn’t all for style), and your brakes going down hill. BMWs (besides the X models) really aren’t meant to tow. I don’t think the 540i will be very happy towing a race car + trailer + all the tools and parts necessary to go racing.

Svend > Flynorcal: pilot, offshore sailor, car racer and panty thief
03/03/2018 at 04:16

As car Guy Twingo tamer suggests.

https://oppositelock.kinja.com/tow-me-down-1609112611/1609771499

Sovande > Flynorcal: pilot, offshore sailor, car racer and panty thief
03/03/2018 at 04:16

Will it tow it? Probably. Is it a good idea? Nope. Quick search shows that there is a kit available that will allow you to tow 4400lbs - 75% rule takes that down to about 3300lbs. If you get a hitch in the US you are limited to about 2000lbs and only 200 pounds of tongue weight since the hitch mounts through sheet metal in the spare tire well. This is why you see most people hauling heavy loads with pickups and big SUVs - it’s the ladder frame construction which allows the frame to carry the weight. Unibody cars don’t have the same capacity.

A trailer with brakes made to haul a car is going to be at least 1000 pounds all by itself - add a racecar to that and you are easily at 3500 pounds - you will probably want something that can tow about 7000 pounds just to be safe.

Twingo Tamer - About to descend into project car hell. > Flynorcal: pilot, offshore sailor, car racer and panty thief
03/03/2018 at 04:28

Here ya go

https://oppositelock.kinja.com/tow-me-down-1609112611/1609771499

TheD0k_2many toys 2little time > Flynorcal: pilot, offshore sailor, car racer and panty thief
03/03/2018 at 04:51

Diesel trucks are BA all on their own and can tow your house if you want. So get one of those and tow 5 cars

MasterMario - Keeper of the V8s > Flynorcal: pilot, offshore sailor, car racer and panty thief
03/03/2018 at 07:15

As long as the trailer is still balanced and you don’t exceed the tongue weight the only thing that happens is working you engine hard, having longer braking distance, and having the trailer “push” the car around a bit more. The physics of towing will just be much more obvious

bob and john > Flynorcal: pilot, offshore sailor, car racer and panty thief
03/03/2018 at 07:26

Yea no, if you are looking to tow a CAR on a semi regular basis you will need either a full sized SUV, a pick up, or an older body on frame wagon (something like a road master)

Ninja edit: now if you wanted to tow a couple of bikes around this would be more then up to the task

Mercedes Streeter > Flynorcal: pilot, offshore sailor, car racer and panty thief
03/03/2018 at 08:12

Since your car does not have an official tow rating, you will have to do what I did.

Look into that car’s community and see what most people with hitches tow. Then try towing that weight and see how the car performs.

If you think the car could do more, you will have to enter into uncharted waters to figure out what it could actually tow.

In my second gen smart, I mounted tyres that had a crazy high load rating and strong sidewalls. I then opened up the intake system for a little more low end torque. I then began renting a bunch of U-Haul trailers (the local corporate office has me on a first name basis) to see what the car could safely tow with minimal modifications without dying or killing anyone.

General rule of thumb with towing with vehicles that don’t have an official rating is that you should not exceed your vehicle’s curb weight or hitch weight, whichever is less.

merged-5876237249235911857-hrw8uc > Flynorcal: pilot, offshore sailor, car racer and panty thief
03/03/2018 at 08:40

I’ve towed a car on a trailer with my Dakota RT back in the day, but I wouldn’t do it again. It had plenty of power and a towing capacity or only a 2000lbs. But I was well into the 3000-4000lb range with the car and trailer. I was able to get the tongue weight down, by backing the car on the trailer, but I should have moved it further back. It got a bit dicey with the Dakota going light in the front end from the weight. Power wasn’t an issue and with the trailer brakes, braking wasn’t a problem either, but the balance of the trailer being off a bit was what made it sketchy. If you get a good lightweight trailer and can position what you are hauling to get the weight to sit right, it won’t be too bad. You will feel it, and your transmission won’t like you very much either, but it could be done. However, you’d be better served to find a real truck to do the towing duties if you’re going to be doing it a lot. That’s what those full size SUVs are supposed to be for, a nice older suburban or a Yukon will serve you well for towing duties, and you have an enclosed rear similar to a wagon. Just my .02, for what that’s worth. I wouldn’t go undersized for a dedicated towing setup. You can, sure, but it won’t be a pleasant time in the long run.

FTTOHG Has Moved to https://opposite-lock.com > Flynorcal: pilot, offshore sailor, car racer and panty thief
03/03/2018 at 08:51

Honestly you’d be way better off with an E53 X5 4.4i of that era that was designed to tow (6000 lb rating) and from all account about the most fun SUV/crossover to drive of the early 2000’s. It’s not quite as pretty or high performance as that E39 but I bet it’d still be a lot of fun and have no problem to win the Corvette on the weekends.

sn4cktimes > Twingo Tamer - About to descend into project car hell.
03/03/2018 at 10:17

Came here to post this exact link.

ITA97, now with more Jag @ opposite-lock.com > Flynorcal: pilot, offshore sailor, car racer and panty thief
03/03/2018 at 11:17

For towing racecars and suitable tow vehicles for doing so out here (especially in the west where altitude, steep canyons, mountain passes, big-time wind and 80mph speed limits are all regular things) tend to be a little different than how the Europeans tow, and tongue weight factors into your tow vehicle selection as much or more than total weight. Even here, what you might be able to live with for towing to a local track 20 miles away over surface streets is different than towing to a regional track 500 miles and a couple of mountain ranges away on Friday after work, racing all weekend and then towing 500 miles back home Sunday night and dragging yourself to work on Monday morning.

Your vette on an open trailer is going to be pushing 700-1000lbs of tounge weight (and 5000-6000lbs in total) pretty easily, and you still have to factor in all the stuff that also into the back of the tow vehicle for a weekend of racing: a couple of sets of tires, a good jack and set of jack stands, a tool box that weighs more than you do, a couple of rubbermaid bins of spare parts and fluids, air tank/compressor, safety gear, a shade structure and chairs, fuel jugs, a table or two, a cooler of food and drinks for the weekend, luggage for the weekend... You end up with a lot of weight in/on the back of the vehicle.

Towing a full-sized, fendered racecar on an open trailer out West, a half-ton truck or 1/2 truck based SUV ends up being the smallest vehicle that works well. When one jumps to enclosed trailers, the added tongue weight and frontal area work out to wanting a 3/4-ton diesel or better. I’ve know a lot of folks who started racing towing a spec miata on a open trailer with a variety of unibody SUV’s like grand cherokees and 4runners, or small trucks like V6 rangers or Tacoma’s. All of them ended up buying a 1/2 ton truck or bigger after not more than a couple of race weekends.

If you’re looking to go racing for real, you should probably budget a coupe of grand for an open trailer and some amount for a truck. Probably the cheapest way to get a set up that will tow well and not be a constant upkeep project itself, is a used 16ftish open car hauler (something with the lowest deck you can find and a dove tail at the back) and mid 90's-mid 00's 1/2 ton truck (with the larger available V8, short gears and factory tow package). It is certainly possible to start of with less tow vehicle, but you’re likely to end up wanting more after a few weekends of marginally stable towing with long stopping distances and not being able to maintain speed up hills.

I actually did this myself. My initial plan when I started racing for real was to borrow the parent’s 99 Dodge Durango to pull my racecar and trailer with. While it had plenty of power with the 5.9l V8, short gears and the factory tow package, it didn’t handle the tongue weight particularly well. It had looong stopping distances and was only just barely adequately stable at interstate speeds. After the second race weekend, I bought an old 91 F-150 with a camper shell to tow with. Even with only the 5.0 under the hood, it was a significantly better tow vehicle simply because it could handle the tongue and cargo weight without problem.

A couple of factors beyond just engine size/power/torque curve come into play. The capacity of the rear suspension is vital, because towing on the bump stops is going to be dangerously unstable at higher speeds. Likewise, given everything else equal, the longer the wheelbase and the wider the track, the more stable the tow vehicle is going to be and better able to control trailer sway. Also, the heavier the tow vehicle, the less influence the towed load will have on it in terms of stability.

Flynorcal: pilot, offshore sailor, car racer and panty thief > ITA97, now with more Jag @ opposite-lock.com
03/03/2018 at 12:42

Thank you. While I would have liked to hear “yessssssss buy the BMW wagon!” this is an incredibly helpful guide to what to do and why. I’m gonna set a Craigslist search that runs in the background looking for a truck with a towing package and quit trying to fool myself.

I’m a little shocked the Durango wasn’t spot on for the task. Seems like it should have been perfect but I don’t know shit about trucks. I’ll just look for something 1/2 ton and try to read up some more.

I remember you buying a new trailer recently. I’ll go back and have another look at what you bought as I know you bought it for similar reasons.

I really appreciate the advice. Thanks again.

ITA97, now with more Jag @ opposite-lock.com > Flynorcal: pilot, offshore sailor, car racer and panty thief
03/03/2018 at 14:07

No problem. If you don’t need a crew cab or 4wd, the selection and prices of used 1/2 ton’s gets a lot better. A short bed will be plenty of space for a race weekend’s worth of stuff. The factory tow packages usually give you the hitch, light hookup, engine oil and transmission fluid coolers and sometimes a bigger radiator. That is all stuff that can be fairly easily added to a truck that didn’t have it from the factory, but I’ve found that trucks without the towing package tend to also have taller gears. Gear ratios end up mattering as much as the engine for towing. The ideal is the bigger V8 and whatever the optional shorter gears were (usually 3.73 or 4.10's, versus the standard 3.55 or 3.15 ratios).

The tahoe/suburban/expeditions can also work well, although the GM full-size SUV’s tend to be sprung a little towards the soccer mom end of the the spectrum. My previous 96 suburban and 99 escalade towed well once I added a set of helper springs to the rear leafs.

I think my trailer posts are under the trailerlopnik tag. I ordered from these guys( http://www.carsontrailer.com/subs/trailers/car-haulers/car-haulers.html ), and they’re actually based in Northern California. I looked for a long time to find someone who would build exactly what I wanted and was West of the Mississippi.

shop-teacher > Flynorcal: pilot, offshore sailor, car racer and panty thief
03/03/2018 at 23:56

The only car you should consider would be a Roadmaster or Caprice wagon, with a tow package. They’re rated for 7000 pounds. Probably better off with a nice 1/2 ton towing package truck though.