How to win a car tug of war.

[@MattBlack6]

Moral of the story next time you are invited to a tug of war, offer all the biggest blokes in the crowd to jump in your car as well and say "hey not only will I win the tug of war I will be able to do it carrying all the heaviest people here"

[@L2SFBC]

Yep indeed play it up as a disadvantage 👍

[@Ding_Bat]

Great explanation. This is also the reason why tractors have 3-point attachments, which not only prevents them from popping impressive wheelies when attaching farm implements, but also loads the rear wheels for better traction. It’s also why tractors have individual brakes for the rear wheels, so the you can still steer with the brakes when the front wheels have too little traction to enforce direction changes. Physics and maths.

[@L2SFBC]

Yes indeed...I thought of going into that but the video was long enough already and I didn't have a good tractor model to demonstrate :-) Thank you for the addition.

[@whatusernameis5295]

the 3 point attachment does not prevent/hinder the attachment from lifting the front of the tractor off the ground. the counterbalance provided by the engine and any weight hanging off the front does

[@Ding_Bat]

Quite correct. However, the 3-point attachment results in less counter weight being required when compared to just a drawbar being used, thus resulting in less overall weight being required on the tractor to prevent the front wheels from lifting up and the tractor potentially flipping over.

[@sixstringedthing]

Vehicle tug-of-war thumbnails are super handy for at least one reason. They provide an instantly recognisable indicator that any given CarTube channel: a) cares more about clicks than it does about presenting correct/accurate information, or b) is run by people who don't actually know they are talking about, or c) both of the above.

[@L2SFBC]

I wish I hadn't read this whilst drinking coffee :-) :-)

[@malachi2371]

I have never seen this subject of torque and horsepower and tug-of-war ever explained this well. Thank you!

[@L2SFBC]

Glad it was helpful!

[@jankreye4698]

Maybe it is worth mentioning that the friction coefficient is lower when slipping compared to non-slip friction. That means wheel spin makes it even worse. For the tug of war experiment; press the brake pedal down until your opponent experiences wheel spin and then start to drive off carefully.

[@L2SFBC]

Every tyre has an optimal slip ratio for traction dependent on the tyre and the surface. Zero slip is never the answer though. If you let the other car get traction and pull you then you are at a disadvantage.

[@fredio54]

Robert knows his stuff. Around 5% slip is typically optimal. The trouble is any slip rapidly turns into excess slip when your speed is near zero. Excess slip immediately turns into liquefied rubber and very low traction.

[@L2SFBC]

But looks impressive!

[@blazbohinc4964]

Remember in Fast and furious when they pulled a 40 tone safe out of a wall with 2 chargers and the cars couldn't do it in first gear so they shifted into 2nd and then the wheels spun fast enough so that the wall around the safe let go. It was the most brain dead scene I've even seen in my entire life.

[@L2SFBC]

Ah yes I forgot about that. Because of course 2nd gear provides more torque....

[@Ocastia]

Great explanation. This is also why Tanks tend to absolutely dominate those pulling competitions, Caterpillar tracks and ~ 60 tonnes of mass, are quite hard to beat when it comes to traction.

[@L2SFBC]

Yes and tanks compete on dirt, on which their advantage is greater over round-tyred vehicles compared to bitumen.

[@BandaMapper]

Glad you clarified the common misconception of: Weight = Grip. Weight distribution is often more important, great video

[@L2SFBC]

Thanks!

[@debluetailfly]

Like you say, it is not just the weight, but the weight over the drive wheels. I saw a video of a 4WD Chevy PU vs a big Kenworth bobtail. They were pulling each other back and forth some but the PU was able to pull the big truck more. Most of the viewers thought the PU could outwork the big truck. The problem was weight distribution and hard compound tires. A bobtail gets terrible traction, but increase the weight over the drive wheels to 30,000 lbs, and it will get traction that would have pulled that PU around the block.

[@L2SFBC]

Thanks, what's PU, PickUp?

[@debluetailfly]

@@L2SFBC Yes PU is PickUp

[@kaleemullah9522]

Wow! You are the real GOAT of automotive industry, Salute....

[@Zankaroo]

Matt from Demolition Ranch also proved this on his second channel when he did a tug of war between his military 5 ton and his armored Suburban. Suburban won on dirt with basic all terrain tires.

[@L2SFBC]

I just watched that. First win was for the Suburban in 2WD...refer my notes on weight over driven wheels. Also, the rope was not level, favouring the 5-ton. And again the host credits the result to torque. No, if it was torque, would have won first time.

[@eirik_halvorsen]

I appreciate your thorough explanation! However I was expecting you to comment on the Ford/Tesla video. The Ford would because of all the factors you listed probably not stand a chance. But the Tesla had a head start, the Ford wheels were rolling backwards when the Tesla started pulling. I find most of the tugging videos on KZbin often are not very synchronised. In my opinion it’s like every other competition, a head start is hard to beat. Would be interesting to hear how science explains that😊

[@L2SFBC]

I didn't notice the head start, yes that wouldn't help. By pitting a 2WD F-150 against an AWD CT it was a silly test to begin with. The explanation of why a head start helps is because the other vehicle then needs to fight against the momentum of the opponent, not just overcome its traction.

[@andyh5666]

Nice explanation. Thank you - I was also pretty facinated with that 747 with a different engine configuration 👍

[@ΑΠΟΣΤΟΛΟΣΧΑΤΖΗΣΤΑΥΡΟΥ]

It's a movie prop, from casino royale amd other movies, it has been stored in the top gear test track what's why it so often seen on car related films

[@andrewahern3730]

I learned about tractive power from trains. They'll often need multiple engines to go up grades, not because they are power limited, but because of wheel slippage.

[@L2SFBC]

Indeed, you can always gear down for more torque and accept a lower speed, but if wheels spin...more power isn't helpful.

[@gearloose703]

With solid axle there is a lot of dynamic things going on which can ruin the tractive effort. For example the other side is more loaded than the other unless suspension geometry is tuned to compensate it. Thus the other side will lose traction first and the drive shafts having some twist will immediately enter into an oscillation causing the axle to bounce.

[@L2SFBC]

Yes indeed, good point. I did not cover that, plus several other factors such as CoG height, tyre pressure, suspension etc. It would be interesting to build a model to demonstrate all the effects.

[@Jason_Singe]

3:35 Shouldn't 3,000x 0.8 be 2,400, not 2,700?

[@JoshMcDonald-q6z]

Robert, I found myself adjusting the volume a fair bit on this video, I thought you’d want to know. That said, I thoroughly enjoyed the content. Thanks!

[@L2SFBC]

Appreciate the feedback, I'll try to be more consistent with the volume next time!

[@MiniLuv-1984]

Thanks, as usual very instructive. All the best for the new year Robert.

[@canoaslan1011]

Great video, The best experiments are the simple ones, that prove the point effortlessly. The situation with the tractor and Landcruiser looks strange at 1st. What the Landcruiser has over the tractor is a very good 4wd traction control, and the tractor has been stripped bare. It has no ballasts at the front or on the wheels, were specially on 4wd tractors there is always ballast on the wheels at worst at the front. It bounces due to the big tyres and being inflated more that usual, Tractors arent designed for hard surface, so they bounce, due to not having any suspension/springs. But regardless, the Landcruiser's traction control allows it to just spin enough very small amounts, but not enough to lose traction, hence even if it doesnt pull it can atleast not be pulled. Or the Rock is driving it and his contract says he cant lose. PS before this one I was watching Wistlingdiesel videos, and I was expecting the Prado to just launch and shread apart LOL or atleast for the tree to break. but that doesnt happen in the real world, unless its a Cybertruck

[@L2SFBC]

My channel is pretty different from Mr W. Diesel :-) Yes, good analysis of the Cruiser vs tractor, thank you.

[@nealesmith1873]

Very interesting! Here in Mexico, ranchers will keep some big rocks at a point just before a hill or streambed that has low traction. Usually they have 2WD pickups. They will stop before the obstacle and put the rocks in the pickup bed, drive across and proceed to their destination with the rocks in the truck. On the way back they will unload the rocks and leave them at the same spot.

[@L2SFBC]

Thanks, that is great! The water would reduce load on the wheels as well.

[@hoyks1]

Aircraft tyres are hard as a rock (upwards of 170psi) and I'd imagine have lower rolling resistance than a standard road tyre. Planes always look impressive due to the their scale V a car, but they are built to be light for the given volume. As shown the VW was full of ballast and I'd bet the 747 had no fuel and the tyres were pumped up to max pressures to give it the best chance.

[@IbbyP]

Yep. At 155 ton it's bare bones 👍

[@hoyks1]

@@IbbyP Yep.Kevin Fast holds the Guinness World Record for the heaviest aircraft pulled by a man: Aircraft: C-17 Globemaster III Weight: 416,299 lb (188.83 tonnes) Distance: 8.8 m (28 ft 10.46 in) Time: 1 minute and 16 seconds

[@andyh5666]

Plus, the specialised small-sized aircraft tenders seem to do ok. They must have weight and torque, along with good friction to back up those big, fully laden jets.

[@Expedient_Mensch]

Great explanation, Robert, very clear and thorough. I just need to comment that anyone that knows what a Newton is, also probably knows the difference between mass and weight....

[@L2SFBC]

True, true...and load

[@BurchellAtTheWharf]

0:29 traction makes a world of difference

[@principal7819]

You are EXCELLENT at teaching

[@L2SFBC]

Thanks! I try to be :-)

[@wohnzimmeraquarium4174]

Very interesting, very good explanation, and there is a practical use. Thanks

[@L2SFBC]

There is indeed!

[@GlennC789]

Honestly horsepower should make no difference at all if you get to choose your gearing. The tiniest amount of horsepower can make any amount of torque at the wheels you'd like. Then as long as you have the required amount of weight and traction you can out-tug an earth mover. So as a test of power... it's pretty stupid.

[@TC-V8]

It's wheel torque or force which is important here - and yes gearing changes this! But no point having more wheel force than the tyre friction can transfer to the ground!

[@GlennC789]

@@TC-V8 Exactly right. There's still a common misconception people have that torque relates in some mysterious but semi-intuitive way to power. People will say things like "power gives you top speed but torque gives you acceleration," which is totally wrong.

[@HetNeSS]

11:10 - double the weight of touareg to ballast? Was there anything left of suspension at all?

[@L2SFBC]

It would be on its bumpstops but at 5kmh on the flat for a hundred metres that wouldn't matter.

[@vincentgoforth6082]

There’s a couple of videos of a single cab red Chevrolet dually diesel dragging semi trucks which I would be willing to say weigh more than the truck. Also more wheels on the ground to the semi trucks. Not sure if it’s the power the red truck had but it must be one exception to the rule. Look it up it is surprising and satisfying to watch lol.

[@L2SFBC]

Got links? It would be easy enough to skew any test, put low traction tyres on the prime mover, reduce its weight, increase weight on the tow vehicle, use an non-level rope...lots of possible tricks.

[@vincentgoforth6082]

kzbin.info/www/bejne/g2WldoWod6aNZqcsi=gdBOruLyeXWN1BTQ

[@vincentgoforth6082]

kzbin.info/www/bejne/nIbKcmyCgranpc0si=08Yzmr8fLo5WhVzS

[@vincentgoforth6082]

Not sure if the links were added but I tried.

[@L2SFBC]

Yes saw them. Pretty easy...weight over driven wheels. The red pickup is clearly heavier so it wins. Nothing more to it than that. Look how heavy it is in the back.

[@robertstuckle6198]

Thank you

[@L2SFBC]

You're welcome

[@GraveUypo]

it's almost entirely on grip, with is a product of weight, contact patch area and uh... tire efficiency i guess. any torque disadvantages can be overcome with gearing, and it doesn't take much for the limiting factor to be grip, so it hardly matter. a 60hp 7 ton tractor will drag a 1000hp 3 ton truck around like it's nothing with proper gearing..

[@SANSIDADVENTURE]

Excellent Presentation and Demo, Thank you and Best Wishes for 2025

[@L2SFBC]

Appreciate the kind words and Happy New Year!

[@doctor_who1]

i'd love for you to explain why the vehicle squats down when i brake boost it just prior to launching it. something to do with the drive shaft and the suspension interacting but how?

[@L2SFBC]

The engine normally turns the wheels as you know. If the wheels cannot move, then the engine tries to the body/chassis around the wheels instead. But it can't do a full 360, it can only compress the suspension. Think of drilling something, if you don't hold the job still it may rotate with the drill bit. Make sense?

[@Ding_Bat]

You also see this in semi trucks pulling heavy loads, where torque from the engine twists the whole chassis out of shape. It kind of tells you that the components in your drivetrain are really being stressed, and if things that are supposed to move cannot move, the only result is breakage.

[@L2SFBC]

Yes and I have a R/C car video here which shows torque twist laterally. Same deal, torque is being applied. kzbin.info/www/bejne/eXzdo6V4rK2DbtU

[@alexandrospavlakos979]

Great video!! Isnt the extra weight a factor, as the vehicle has to generate more power for its own overall weight??

[@L2SFBC]

Yes, but it's fractional. A vehicle with rolling reistance of say 0.04 weighing 2 tonnes requires less torque to move than a vehicle with the same 0.004 but of 3 tonnes. Any modern vehicle has way more than enough torque to spin the wheels so that fact it requires say 20% of the its torque output instead of 19.5% is not relevant. Essentially the limiting factor is grip, not torque/power. Need a lot of grip before torque becomes the limit, and even then just gear down and increase torque at the expense of speed.

[@alexandrospavlakos979]

@@L2SFBC Thanks! Its understood. Happy New Year!

[@vasil7410]

Cool models

[@davidberry2542]

At 3:40, 3000 x 0.8 = 2700. Hmmm… not what I get. Just being picky - we’re all human.

[@L2SFBC]

oops sorry about that!

[@justonlyme6121]

Torque is a measurement of static rotational force, hp is the actual work being done hp=tq x rpm/5252, but let’s not forget archimedes as gearing plays an even more significant role than either. As an example, think of trying to get a loaded truck starting off with the same gearing a car has, or getting a 1hz up a steep track in high range, So torque is a meaningless number when talking about engine power, except to use it to calculate horsepower.

[@L2SFBC]

" So torque is a meaningless number when talking about engine power, except to use it to calculate horsepower." - do you want to edit that sentence :-)

[@justonlyme6121]

@ it’s meaningless in application. Power at a given rpm with gear reduction is what it is. You don’t even need to know the torque number.

[@turtlealberigi]

Hp is not a measurement of work. Work is force over a distance, there is no time component. I understand the point you are trying to make about hp and gearing and agree that in a race, hp is more important than torque. As the video is explaining in a tug of war, hp is not very important.

[@operation4wheelz]

I think the TRX4 needs a GVM upgrade

[@fredio54]

You failed to define "win" - the winner in my tug of wars is the person who does the best burnout. Do you think a 100 series vs immovable object could smoke all 4 in low ratio centre locked? I intend to try :-D

[@L2SFBC]

Please send me the video!

[@andyg9991]

Great demonstration, but does your wife roll her eyes when you start to pull out the remote controlled cars?

[@L2SFBC]

I do not have a wife, and if I did, she would be a woman who would appreciate R/C cars for the wonderful models they are :-)

[@andyg9991]

@@L2SFBC No wonder you get to do all this cool stuff lol

[@wayando]

What about the color? ... We all know red cars are always stronger, everything else being equal.

[@L2SFBC]

:-)

[@markbroad119]

So you're going to stand there and tell me that "The Fast and The Furious" isn't at all real? 😅 Yeah not s very good example of what cars really do. "Danger, pressure to manifold!!!" 🤣 You have stated the truth and I like that about you. If only the majority of people could understand physics

[@L2SFBC]

Well, everyone knows F&F isn't real...but I don't think they know which parts aren't real, and the degree of real-ness. That is where it gets difficult, when unreal scenes are shown but they are based in a nugget of reality.

[@fokkju4869]

Not really relevant for understanding the topic but small nitpick here; 3000x0.8 gets you 2400 on my calculator =p

[@L2SFBC]

oops yes you're right sorry

[@fokkju4869]

@L2SFBC Oof, sorry right back at ya. Reading that back reminds me too much of my teenage internet behaviour. Just a small typo and there I go ... Anyway, thanks so much for making these videos, big fan. Been checking in since the wide vs. narrow tyres for off road video. I really love the mix of real world testing with actual data and then the simple to understand physics explanation and your great examples. Thanks as well for this specific topic. I mostly deal with snow where I'm from so I'm really interested in the physics of traction on loose surfaces and flotation/ground pressure. I'm rambling now, have a good one.

[@L2SFBC]

I don't mind you pointing out the error at all and wish I'd not made it, but it is not significant enough to warrant me deleting it. I would prefer to know it's there and take no offence, how could I, it is a clear eror. As for loose surfaces, check out my Sand Fundamentals video. Some of that is quite applicable to other compression terrains like snow.

[@cinnamonrollypoly]

I'm going to skip all the nonsense and say that it all boils down to traction. That's pretty much it. I HATE these tug of wars because all they really prove is that you have better traction at the back... which is pointless when you consider most of these are done with pickup trucks, which have hardly any traction in the rear anyways, because they're designed to have a payload in the bed, or have weight on the hitch. It's incredibly stupid.

[@L2SFBC]

Well, the pickups are generally 4x4s, in 4x4, so the "light rear" doesn't really work. But yes the tug-of-wars are pretty pointless. What does it prove? Nothing really.

[@toasteroven8588]

This is off topic, however: Regarding steering, it may be better to pull on the steering wheel instead of pushing as many believe human arms have better precision and control when pulling on stuff. An example of this would be the popularity of Japanese style wood saws which cut when pulled back. Food for thought.🪚

[@L2SFBC]

Absolutely, and I demonstrate that here kzbin.info/www/bejne/fpPTYoWLnsaGhtE