You’re Probably Running The Wrong Tire Pressure
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- Опубліковано 4 лют 2025
- The chalk test has been around for ages and although it might not be perfect, it works really well. Here's how to use it to find the correct air pressure for your specific vehicle.
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I cannot get enough of your 4Runner. Beautiful as always and the way it sounds just very good..
Thanks! That's why it hasn't really changed much over the years - I'm happy with it the way it is!
I have a 2020 4runner with 17 inch rims. and the door jam still says 32psi which imo is way too low . I run at least 35psi because every winter when the temperature gets reallly cold...the low tire pressure lights come on.
Muk Boots... must be a Candian thing :) imma use that from now on.
Chalking works great. I find an empty, flat parking lot and drive only forward. This eliminates any error from road crowning (plus I have a short driveway) and I can drive a fair distance. Driving reverse can change toe-in, although it may not matter a lot.
Using an online tire pressure calculator anyone can look up, and having a similar vehicle/tire combo as you it recomended 38psi. Works well so far, even wear after a year. Off road I air down to 18. Enjoyed the video, thanks.
What site did you use?
This is a very good, practical video. One bit "missing" though is your "ideal" tyre pressure changes depending upon the load you're carrying.
For example, your unladen idea pressure might be 38 kg all the way around. Then you load up for camping. The back might need 44 and the front 40. You load up for a big trip, plus hook up the boat and gear. You might need 55 in the back and 45 in the front. I change my tyre pressure by eye, looking to see if I have even contact. The chalk is good though. It will build up your confidence.
70k on MT Baja Boss AT on my duramax pulling trailer crouse country 30k miles of there life. Got loaded pressure and unloaded pressure. For rear, front always stayed same and did rotation 5k & 7k.
Good luck with those dura tracks! They are get noise when they start cupping! They came on Rebel, they were great until they started to wear down. The newer version RT looks a lot better with closer treads! Good luck buddy!
When going from a "P" rated to "LT" rated, it takes MORE tire pressure to handle the same amount of GVVW of the vehicle. It is interesting that the heavier sidewalls take more PSI to maintain the GVWW. I had a long call with BFG on this topic and they sent me the chart to cross compare my trucks GVWW to what PSI on the LT series tires to run.
I came upon this formula years ago and it has served me well.
Tire Pressure Calculator
(((GVWR+DW)/(4*ML)*MTP))=ATP
GVWR- Gross Vehicle Weight Rating
DW- Driver Weight
ML- Max Load
MTP- Max Tire Pressure
ATP- Approximate Tire Pressure
This makes a great starting point, and gets you to within 4 psi +or -.
One major thing to check! Be sure you don't excede the max pressure on the sidewall of the tire. Someone I know took a 3/4 truck in and had a large size off road tire mounted. Didn't get too far on highway and had a blowout. Installer put 75 psi into a tire with max pressure of 40. Luckily no one including the installer was hurt.
Passenger tires are generally load range "B," if it matters.
Great video and great information 👍🏽!! Also great looking tires on the 4runner!! Are they A/T? What model wrangler tires are they? Thanks
3:53 I-6 would sound waaay better . . but we digress . . . Good video, good advice. Well done.
34-35 psi for me. 33 in winter. Falken AT3W Load C.
I used to run K02s at 40 psi, Load E, never did a rotation. I didn't know tires back then.
Water works better. Hose the tire down. Drive straight foward a few feet on dry section of driveway. Read the tire print left on your driveway
Wouldn’t you want to do this with tires at running temp, or does that not make enough of a difference to bother?
I've heard arguments for both options, I always adjust pressure when cold so I do the test then too
You can just get down low to the pavement and see when your outside edge of the outer lugs come in contact with the pavement, then you know you have full even contact.
I just look at contact pattern on the tires after i dive them a few miles or a couple of blocks. It's not hard to dial in your tire presser.
Yay! More rims and tyre videos!!!
@@Groots22 I knew you'd be happy 😂
Over 55,000 miles on my K02 running at 50psi cold on my WK2
So what psi are you running with that 285/70/r17
I recommend conducting this test at higher speeds, as tire deformation changes significantly with speed especially centre/edges.
Yeah, faster than I did it but not so fast that you have to make steering adjustments
@CanadianGearhead loved your video btw!
When I do the Chalk test I look at the ground that I run over to see if the pattern has the whole width of my tire. Its not as good trying to look at the tire itself. Like on a 2020 Tundra TRD Pro with Goodyear Duratrac 285/75R18 I had to go down to 34 PSI Front and 31 PSI Rear to see the full width of my tire printed on the black top. Anything more and I wouldn't see the outer edges of the Duratrac print. 40K on my tires now and they are still wearing even with 5 tire rotation every 5-6K. Hope this helps someone.
what pressure are you running then?
@@thecount1001 Mine were at 32 PSI here, going to add a bit 👍
lol I know I was like "Hey wait a second, what's the PSI though! I have the exact same tires on the same 4Runner". Glad to know my 35ish is in the neighborhood.
32psi is way too low for a 4 runner.
Or, you can just just email the tire manufacturer, give them the make and model of your vehicle and tire size, and they will tell you exactly what your front and rear tire pressures should be.
I imagine the “perfect psi” is a pretty large range. I’ve tried this a few times and all the chalk wears away
Yeah, as long as the pattern is even, you're good
Yeah this is a test for the less smart to find out they have extremely high/low pressure
I was taught that the bill of the cap goes in front. Think of it as a shade for your eyes.🙈
C'mon dude, really.
It's an 80s-00s kid thing. It's hip, man.
For every p.s.i. Increase, the tire temp decreases. Heat equals wear. Higher pressure equals higher load capacity and decreases rolling resistance. Tires are 50% of the ride quality, shocks 50%. Stiff shocks and hard tires equals a rough ride. Running 80 p.s.i will keep tires cooler, lessening wear, assuming suspension geometry is correct and proper rotation. The issue with that is the vehicle is absorbing road shock and its not great for cab mounts, hinges and latches and most everything else. Modifying any suspension has negative effects. Pick your poison.
No one should be running 80 psi Cold Inflation Pressure on a passenger vehicle. The recommended tire pressure is printed on a label affixed to the driver door jamb. Tire makers and vehicle manufacturers have done the work for you. 80 psi is the suggested Maximum Cold Inflation Pressure should you be transporting a load weighing such that it puts the vehicle at it's GVWR.
@@applesbighatranch6906 4 door pickup trucks are passenger vehicles. 10 ply load range E tires are very common on them. Obviously you don't inflate a tire past its maximum. Although i have always run 40 p.s.i in 35 p.s.i tires.
What ambient temperature/climate is this information best applied?
the p.s.i number in the door jamb in for the rated GVWR. Which is set based on the frame, suspension differential and tire weight rating. And to maintain ride quality, in passenger vehicles. Ford lowered the p.s.i number on their suv, a long time ago, and they had a rash of tire blowouts from exessive tire temperature, killing people.
Stock tires yes, aftermarket use the psi on the tire. Different strokes for different folks.
@@richarda996 As mentioned in the video, the marking on the tire is the maximum permissible, it's very unlikely that you want it that high.
Cool. Never knew about the chalk test before... learn something new every day : ). Just out of curiosity, what psi are you running with your tires?
@@troybabs Mine are a little low right now at 32 PSI. I like to run them a bit on the harder side (higher 30s) to improve fuel economy a bit
Very helpful! Never had heard of this.
You are the Bannana King Charlie ❤❤❤
What’s the part number on the original wheel center cap? Mine are missing.
Did you say a V8 4Runner?
4th Gen
*Respect*
Super helpful!
Thanks for watching!
This is something that irritates me, i have new tires put on my truck that are rated at 80psi and the tire shop says they cant inflate them beyond the recommendation on the vehicle which is 35psi on the stock tires. This is absolutely stupid and i end up having to drive home on half inflated tires and inflate them myself.
pretty cool bro!
👍great old school hack for the newbies I get 50000 with some left bald around 60000. Rig looks good for a rice burner. Costco tire center takes care of the balance & rotation where I’m from .
It’s not rocket science, i would run 38 unloaded, 40 front 42psi rear loaded on those tyres.
Just run what the manufacturer says on the inside of the door🤷♂️
Cool
run is the wrong verb, you dont 'run' a tyre pressure. you inflate your tyres to your chosen pressure, and drive your car. you dont 'run' anything apart from a race or a bath.
I run 36 psi Cold Inflation Pressure in my 34 X 10.50 X R17LT D Load Range to match the Load Capacity of the OEM P-Metric tire fitment. Seems my earlier comment was deleted, perhaps because I recommended an online tire pressure calculator in the name of SAFETY. Oh well. What can you do.
@@applesbighatranch6906 Take it up with UA-cam, I didn't delete anything.
Remove the stick from your rear end.
Engines cant run because they dont have legs DUHHHH
Not to worry pal, we run tires around here, you can drive your tyres all you like. Oh ya, and how far does your bath run? AND your shift key is broken. 🙄