windborn
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Post by windborn on May 23, 2017 17:03:47 GMT -8
Hi y’all. I’m in the market for a new tow vehicle. I’ve read through a lot of the posts here but still have a question: what should I be looking for in regard to horsepower and torque? Or is it mostly tow capacity and factory tow packages that matter?
My trailer is fairly light: 1500lbs before we beefed it up a bit, though I also took out a 25-gallon water tank. My Mazda Tribute with a factory tow package, rated for 3500lbs, did alright on my cross country trip, but I think I need something a little more powerful next time. (Also, “alright” is generous as I spent a lot of time at the mechanic on the way down and drove 45-50mph or slower on the way back.)
In looking at potential vehicles (all small-ish SUVs), I see the engine size, and understand that bigger mostly means better in this case. And the tow capacity is pretty straightforward. (Most of the cars I’m looking at are 5000lbs.)
But I don’t really understand the horsepower and torque. I have a vague understanding that torque is what you need for towing? (Please correct me if I’m wrong.) But it’s hard for me to compare 200 hp @ 6000rpm (Mazda Tribute) to 183 hp @ 4800rpm (Toyota 4Runner). Or 200 ft-lbs @ 4750rpm (Tribute) to 217 ft-lbs @ 3600rpm (4Runner) since I have no clue what any of that means. I get the sense that the rpms in those ratings are when it’s at it’s best (again, correct me if I'm wrong), but how would that affect my towing experience?
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Post by vikx on May 23, 2017 22:09:59 GMT -8
I think 5K capacity is minimum for any tow vehicle. Factory tow package is VERY IMPORTANT, since it meets the specs for that brand's tow capacity. The larger the engine, the less stress when towing up hills. For me, that means V8 and I consider a 5.3 "small". (322 cu in) Ah, for the old days of cheap fuel...
As far as torque, to me it means what the drive train will deliver. For instance, a low geared rear end provides more power to pull but less high speed. A smaller engine will struggle with a low rear end; it relies on power from RPMs rather than torque. A "torquey" motor delivers more bottom end (or off the line/ start and pull power) than a high RPM motor. The turtle has more torque than the hare...
I'm sure our resident car addicts can explain this better than I can. All I know, is: I want POWER, lots of CUBIC INCHES and enough TORQUE to haul the mail. Heck, engines aren't even described in cu in anymore..
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RinTin
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Post by RinTin on May 24, 2017 5:22:06 GMT -8
Problem is, the peak HP and torque numbers can be misleading because they are developed at a high RPM, much higher than the RPM range you typically drive in. Yes you can tow with a V6 engine, but as you have discovered, they don't quite cut the mustard. No matter what, if you have an automatic transmission, be sure it has a good transmission fluid cooler. Towing is hard on automatics. I'm with Vikx, V8 all the way baby, the bigger the better for towing.
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nccamper
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Post by nccamper on May 24, 2017 5:46:40 GMT -8
I offer a third thumbs up for the V8. I know there are new V6 turbo charged engines that can deliver high HP but I'm old school and turbo to me means stress and something expensive that can break.
I learned the hard way about tow ratings. When they say 3800 pounds they mean on flat ground without driving into a heavy wind. As more knowledgeable members told me, cut the tow rating provided by the car maker in half. That's the comfortable tow rating.
After one hour towing with our Ford Ranger I knew a V6 wasn't going to do it in the mountains. I bought a Tundra with a V8 5.7L engine and factory tow package. Even heavy grades hardly slow me down. And the transmission doesn't drop into high gear as it struggles to keep up.
Another thing to consider is wheel base. When a semi raced by our Ford Ranger the wind really rocked the truck and camper. With a Tundra I hardly notice it.
Is the 19' long Tundra ridiculously big? Yes. Is the fuel economy lousy? Yes. Is the extra space in a pick up great for gear? Yes.
That reminds me of a riddle. How do you turn a $100 tent into a $40,000 hobby? Buy a vintage camper.
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windborn
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Post by windborn on May 25, 2017 4:56:50 GMT -8
Haha, I don't like that riddle too much nccamper I hear y'all on the V8, and in a perfect world I would buy a big beefy truck and have another daily driver on the side. But I spent most of my savings fixing up a little aluminum box so I need to find something in the middle. And be ok with driving really slowly when I'm towing I guess. So, if I'm limiting myself to a V6, does engine size make a huge difference? My Tribute is only 3.0L. So would a Cherokee's 4.0L be a lot better? Or only a little better? (I know these are probably impossible questions to answer, especially since I'm looking at older, used cars. But thanks for sticking with me.)
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RinTin
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Post by RinTin on May 25, 2017 6:22:52 GMT -8
There's no replacement for displacement, so yes, engine size matters. I had a late 90's Chevy Astro with a 4.3 liter Vortec V6 that we would load up with camping gear, 4 kids and towed an 18' speed boat up and over mountain passes. The boat was full of gas and stuffed with more gear so we were really pushing that van. We only struggled on the very steepest hills. Overall I was surprised and quite impressed with how well it handled the abuse I threw at it. I believe the 4.3 motor was available through the 2013 model year. Fuel economy was 16-18 mpg if I recall correctly.
Based on my experience, if I were limited to a V6 for towing, I'd be looking for a 2-wheel rear drive vehicle with that 4.3 Vortec engine. All wheel drive breaks more often, gets less mpg, less power to the ground and isn't well suited to towing. I'd get the biggest radiator and transmission cooler available. A limited slip rear axle would be nice to have and maybe even an external engine oil cooler. These are things that can all be added after purchase.
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ruderunner
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Post by ruderunner on May 27, 2017 3:52:19 GMT -8
Here's a way to look at torque vs horsepower:
Torque gets you moving
Horsepower tells how fast you can move
The reality is that horsepower is a calculated number based on torque and rpm. Formula1 cars make about 1000 hp but its at 10000 (yes 10000) rpm. They can go fast but have a hard time geting moving at all. My diesel only makes 160hp but also 400ft/lb of torque. It can move just about anythinig I feel like hooking to it (including things I shouldn't) but tops out about 65mph when towing.
I'd be more concerend with having higher torque at a relativly low rpm (3000 or less) Even 160 hp can move 12000lbs at 65mph. Speed when towing isn't necessarily your friend, slow down and enjoy the trip and scenery.
I'd seriously consider finding a 10-15 yr old half ton pickup or suv to use for towing. They can be found fairly cheap, shouldn't need much in repairs and can sit with the ttrailer when not needed.
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Post by vikx on May 27, 2017 21:45:02 GMT -8
Take a look at Trailblazers. Ours is an 08 and turns on a dime. Rated at 5K, it does fine with our little vintage trailers. The 5.3 V8 has a "gas saver" mode that helps around town mileage. I love this vehicle.
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hairba11
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Post by hairba11 on May 28, 2017 10:32:58 GMT -8
Horsepower is how fast you can go, torque is how quickly you get there? Looking at the numbers you gave for the tribute and 4Runner, the 'yota is giving very similar numbers at 1000 fewer rpm. It will be working much less hard to pull the trailer. The 4Runner lineage and driveline was based on the t100 pickup. The Mazda tribute (Ford Escape)was the station wagon version of the 626 (ford probe) at least into the mid 2000's
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cowcharge
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Post by cowcharge on May 30, 2017 9:19:28 GMT -8
HP numbers are always quoted at the sweet spot in the RPM band, which is usually quite a bit higher than you'll ever hit in normal driving (unless you're into caravan racing). 6000 rpm? That would be like having a giant fly buzzing around my ears. My V-8 F-150 on cruise control turns about 1250 rpm at highway speed until it hits a hill, then it goes up to around 2200-2400 when it downshifts.
I wouldn't get too lost in those numbers between such similar vehicles, they're more useful to marketing departments than drivers. The difference between the two quoted vehicles' engine specs, as far as just torque and HP are concerned, isn't enough, IMO, to override specs like a longer wheelbase for stability or cargo room or reliability. The chance that 17 HP is going to make a big difference towing a camper is very small unless you're operating at the extreme limit of the vehicle's towing capability, in which case you should have bought something bigger anyway. What bothers me the most is that the Mazda doesn't hit that max power until 6000 RPM. That to me implies slow takeoffs and a shorter lifespan if you dip into the power a lot, say when matting it to enter a crowded highway from a short on-ramp. And I just don't like the sound of high-revving motors that make the door handles buzz and the old french fries leap out from under the seats.
Torque gets you moving, it fights inertia, while HP is more an indication of how hard your motor will have to work in general, although it's hard to entirely separate them. A really "torquey" motor will allow you to take off from a dead stop in 5th gear without stalling, or allow you to accelerate to pass another car without downshifting. A high-HP motor will be strained less in every aspect of driving. It will run cooler and last longer pulling the same load than a motor with fewer HP.
Torque is like the force required to get a big heavy couch to break free of friction and start sliding across the floor, while HP is more like how fast you can slide the couch after you get it moving.
As for 6 cylinders, it depends on the motor. I towed my 3200-poundish 22.5-footer with a 90s Ford van that had a big ol' straight six, no problems whatsoever. That's what the PO used as well, and when he towed it from NH to ME for me, he was only ten minutes behind me after 100 miles. I know, Ford doesn't make straight sixes any more. Too bad, they were great motors.
Turbos, meh. Too much turbo lag, you don't get the power until the revs go way up, which would annoy me greatly (along with those behind me) every time I took off from a stop sign (sounds like the Mazda would do the same thing). I had a turbo bike once that was a dog until it hit 3500 rpm and the turbo kicked in.
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cowcharge
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Post by cowcharge on May 30, 2017 9:21:55 GMT -8
I think 5K capacity is minimum for any tow vehicle. Factory tow package is VERY IMPORTANT, since it meets the specs for that brand's tow capacity. The larger the engine, the less stress when towing up hills. For me, that means V8 and I consider a 5.3 "small". (322 cu in) Ah, for the old days of cheap fuel... As far as torque, to me it means what the drive train will deliver. For instance, a low geared rear end provides more power to pull but less high speed. A smaller engine will struggle with a low rear end; it relies on power from RPMs rather than torque. A "torquey" motor delivers more bottom end (or off the line/ start and pull power) than a high RPM motor. The turtle has more torque than the hare... I'm sure our resident car addicts can explain this better than I can. All I know, is: I want POWER, lots of CUBIC INCHES and enough TORQUE to haul the mail. Heck, engines aren't even described in cu in anymore.. C'mon Vik, get with the 21st century and learn the liter conversion!
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Post by vikx on May 30, 2017 20:11:15 GMT -8
I have to look it up every time. I thought our Trailblazer had a 350 for a few years there...
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Post by vikx on May 30, 2017 20:12:46 GMT -8
Another example of Torque: you know when you turn on a smaller vacuum? Maybe a round one? You know how they sort of leap and try to spin? That's Torque.
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windborn
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Post by windborn on May 31, 2017 16:02:14 GMT -8
Thanks so much, y'all! Lots of great advice here and I'm understanding things better.
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Hamlet
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Post by Hamlet on Jun 1, 2017 8:25:25 GMT -8
I'm going to ompletely ignore the torque/horsepower issue...
We tow Hamlet with a 2009 BMW x-3. It's a 6-cylinder, rated for 3500 pounds, which is over double what our loaded weight is, iincluding people. It has a "sport drive" option, which allows us to shift gears as a manual and that's what we use when we tow. We've never had a problem, even in mountains, but we dont ever drive over 60 mph when we tow anything, anyway. Stopping hasn't been a problem, and the engine stays cool, even in the summer. We don't need a big vehicle because we don't carry much. The most loaded it has ever been was this past weekend when we had four adults in the car and a bunch of stuff in Hamlet. The fuel economy isn't great while towing, 14-18 mpg, but it's worked for us since we pulled Hamlet from NE to SW Washington eight years ago.
You need enough torque to get going, enough braking power to stop, enough maneuverability to move around, enough cooling to keep from burning ouT your engine, and enough common sense not to drive like'Mario Andretti. Remember to add the weight of people and gear in the tow vehicle to the equation. A good rule of thumb is to double the fully loaded weight. Some folks carry barbecues, tables, ice chests, etc., so a bigger tow vehicle is necessary, but if you like to travel light, you can get away with a little less.
Your trailer is probably around 1600-1700 lb in its beefed up state. Add 300 pounds of food and gear and 300 pounds or so of people. Minimum tow capacity would be a bit over 4000 pounds.
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