Tire Pressure

[SeniorCitizen]

I've been reading lately in miscellaneous forums that folks are inflating their drive and front tires with pressures of 8-12 PSI. I have a Hustler X-ONE, and for all of these years I have been inflating my tires with the max pressure embossed on the side of the tire (20 PSI rear, 28 front). It never occurred to me that PSI made much of difference in how easy or hard it is to mow the lawn as well as impact the finished look. I'm also wondering would that diminish the scalping I've done when I turn the machine one way or another, and maybe keep me from getting stuck in the mud every so often? I've been using this machine for 12 years, and now I feel like a dope for not knowing this kind of stuff!

If you haven't , consider a chalk test to determine which way you like for air pressure ..

 

[Skippydiesel]

The above video may assist in an initial tyre pressure setting & could work well for mower tyres BUT does not accommodate the inevitable heating (pressure rise) of the road vehicle tyre in work.
Further - most unladen (just driver & front passenger) vehicles will be heavier over the front axle (need higher pressure) than the back + lower pressure - this was not addressed.
A decent tyre supply store will be able to suggest an initial tyre inflation pressure. This should be followed up (as per video) with say monthly checks for wear using a gauge and tyre pressure adjusted accordingly.
A quick assessment of tyre pressure can be done when on a high speed (freeway) trip. When you pull over for fuel/comfort stop - place your hand on each tyre - they should be evenly warm (all same temperature). If too hot to keep hand on = pressure too low - Check pressure it will be high due to heating - add at least 10 psi to each tyre - make sure they all read the same (If a single tyre hot you have an air leak= change wheel). If tyres cold reduce pressure .

NOTE:
# Uneven tyre wear can also be caused by poorly aligned front wheels (camber, caster, toe in/out), worn shock absorbers, poor wheel balance
# Heavy loads and towing will require higher pressures in rear tyres - return to normal when no longer towing/carrying load.
# Fuel station air pressure gauges are notoriously inaccurate - carry your own gauge, for consistent pressure readings (I like the little electronic digital ones) and always check cold tyre pressure (hot is unreliable)

 

[GrumpyCat]

Do you run maximum tire pressure on your car tires? I hope not. It is the same for a mower.

Yes, actually. Tesla specs 42 PSI and the tire also says max inflation 42 PSI.

Same for my Yamaha street bike's rear tire. Front is under the tire's max.

 

[Skippydiesel]

Yes, actually. Tesla specs 42 PSI and the tire also says max inflation 42 PSI.

Same for my Yamaha street bike's rear tire. Front is under the tire's max.

Fair enough. However this is generally not the norm.
For the most part: Road vehicle tyres are run well under the manufactures Max pressure. Max pressure rating being the maximum safe inflation , usually for Max load situations.

Motorcycles and to some extent mowers & other off road equipment are not load carrying vehicles (ie the load does not vary with usage or equipment). In these cases the Max pressure can also be the recommended operating pressure. Some high performance sports cars also run their tires at Max pressure for the same reason - they do not generally carry much in the way of additional load.

 

[7394]

Book & under my seat are tire air specs.
25 F
8 R Works for me. Also changing tire air pressures does change blade height accordingly as well.

 

[Skippydiesel]

Book & under my seat are tire air specs.
25 F
8 R Works for me. Also changing tire air pressures does change blade height accordingly as well.

Forgive my ignorance - What is 25 F?? & 8 R ??

 

[kbowley]

I run 5 PSI in the rear and gives a MUCH better ride. fronts I put 8 PSI. This is on my Toro time cutter 50" fab deck.

 

[GearHead36]

Re: chalking video... if you REALLY want to find the best tire pressures for your vehicle (I doubt this would work on mowers), get a tread depth gauge. Then check your tread depth every 1000 miles. Inside, middle, and outside in 3 places on each tire. 9 measurements per tire. If the middle is wearing faster than the outsides, your pressure is too high. If the middle is wearing slower than the outsides, your pressure is too low. If the outsides aren't wearing the same, you have an alignment problem. This takes much more effort, but it accounts for your vehicle, your driving, how & where you drive, etc. I've done this on one vehicle after I had a blowout on the interstate due to an alignment problem. After replacing tires and suspension pieces, I kept an eagle eye on the tires for a couple thousand miles.

 

[Skippydiesel]

I run 5 PSI in the rear and gives a MUCH better ride. fronts I put 8 PSI. This is on my Toro time cutter 50" fab deck.

Thanks for the reply.
If not already done - Be sure to set your deck/blade cut height for the tyre pressures you are routinely using.
High pressure in the front tyres, may be changing the angle of cut, by lifting the front of the deck relative to the back.

 

[DK35vince]

I run 8-9 psi front and rear on my zero turns.
Smoother ride IMO.