Tire Pressure

48Sed

What pressure should I run in 215/75R/15 radial tires used on a 48 Commodore? should I keep the front and rear the same?
Thanks

[Deleted User]

I believe I have the same radial tires on my '53 Super Wasp and I keep them at 35lbs for the front and rear.

commodorecollector

My 54' has the original factory sticker on the radiator core support, it says: 26 lbs Front COLD, and 24 lbs rear COLD. After city driving pressures will be 3 lbs higher and after highway they will be at least 5 lbs higher.

Lee ODell

Having spent most of my working years repairing suspensions, wheel alignments and balancing tires as a mechanic and shop owner I have never seen a tire seperation from a overinflated tire. I have seen 1,000's of ruined tires because of under inflation. It is a greater problem with radials than with bias ply. Far to many cars came into the shop with tires 15 psi or more under max tire pressure. Usually resulting in having to replace one or more tires because of tread seperation even with as much as 80% tread life left.

As a rule I recommend starting with max. tire pressure with tire cold for best tire wear especially with radial tires. Keep a tire pressure gage in the car and check pressure regularly. Tire pressure will change between summer and winter because of outside temperature changes. Don't check tire pressure after driving because the tire will be hotter with result higher tire pressure. That is normal. Alway check when tires are cold.

What is max. tire pressure?
I have see max. tire pressures on tire side walls marked any where from 26 psi to 55psi. Most are around 35 or 44psi.
If you look on the tires side wall you will find alot of information. Among that information is the max. tire pressure for that tire. Use that tire psi to inflate your tires no matter what car you have. That will give you the most miles of tread wear life.
Not all brands of tires with the same psi will ride the same (comfortably) or have the same tire mileage. Just remember, if you reduce the tire pressure for a smoother ride, the life of the tire will be reduced. I generally do not drop tire pressure more than 2psi below max. tire pressure. Radial tires require good tire pressure to keep the steel cords from squrming which results in tread seperation.

Above all do not buy the cheepest tire. Get good quality tires. Even with my experience and new better I went cheep once. A wind gust hit the side of my 72 Chevy Caprice on the freeway and I was out of control taking up 3 lanes to regain control. Even without the wind it was a poor handling car because of the tires, it handed great until the change. Before I could change the tires a drunk totaled the car the next night while it was parked in front of the house.

I hope this will help you decide.
Lee O'Dell

lostmind

Good advice Lee . So if you don't buy cheap tires , your car won't get totaled when parked in front of the house? LOL
Your advice matches my experience, 47 years as auto tech. Best to start at max pressure , come down 2 pounds at a time if it feels a little "loose" .
Seems like most new cars now are at least 35 pound recommendation.

SuperDave

Lee gives some good advice. Having been a shade tree mechanic for .. well ... a long time. I agree that he knows his stuff.. Ignore the sticker on the door. Listen to what the tire manufacturer says.

Lee ODell

lostmind - when I read your comment i LOL. Couldn't help it. That must be it. It has been 15 yrs and I haven't had a car totaled in front of the house since. Thanks for the humor.
Lee O'Dell

By the way I forgot to mention I was only driving 45 MPH when the wind blew the car out of control on a straight uphill streatch of freeway leaving Palm Springs. The car was so ill handling with those PET BOYS $99 SALE for 4 tires special. That was one scary ride and was glad I wore seat belts and didn't hit any vehicles. iiiii learned a valueable lesson. CHEEP TIRES can be hazadous to your health.

[Deleted User]

Walt with his very expansive radials, $135.00 each, set at 40 front and 38 rear with cross country driving, bought in 1999 went 80,000 miles and replaced in 2007 with the same name tire, only now it cost $155.00 each and still run the same pressure. Now have 62,000 on them and still look new. Always check tire pressure cold before you leave the garage. Pays to have an air compressor. My cross country driving is at speeds up to 90 MPH. Stay away from COKER for high speed driving. Walt.

Lee ODell

Walt
Will you let us in on the brand and model tires your car is wearing? Sometimes some of us still like to drive fast on occation even though I have slowed it down some. I'm not in such a hurry to get somewhere anymore.
Lee O'Dell

Huddy42

When checking tyre pressure at the local servo, DO NOT RELY on their gauges, I checked mine at the servo yesterday and their gauge was 6lb out, I have two hand guages I check mine with
one when pumping up at the servo and one later on at home. This is in Australia at least, don't know if you guys have better equipment over there, but, the way some drivers abuse these guages at the servo stands to reason why they are not accurate.

bob ward

I have always run my stepdown radials at 35psi, my reasoning being that modern cars of a similar weight typically specify tyre pressures of 35psi. Having read Lee O'Dell's comments though I might start reading the sidewalls.

I take zero notice of 60 year old tyre pressure recommendations.

StillOutThere

The absolute worst thing one can do re. tires is to run modern radials at the pressure recommended in your 60 year old owners manual or some factory decal intended for antique bias plies. About the only similarity between 60 years of tires is that they are round with a hole in the middle to mount on a wheel.

48Sed

Is the pressure stated on the door sticker for new cars calculated for best ride not tire wear and handling?
I was once told that OEM tires don't last that long because they want a nice smooth ride on your first test drive so the rubber is soft for that reason compared to replacement tires.
I see some cars today with low profile tires and wonder what the ride must be like.
Thanks

RL Chilton

Low profile tires= worse ride on the road.

48Sed

Running a little higher pressure in the front would make the steering a little easier would it not?

[Deleted User]

Lee, I have COOPER radials, 275/R X15 and run at the pressure I stated. At 90 MPH on the highways you steer with one finger, cracks or bumps in the road make no difference. Walt.

Lee ODell

Thank you Walt. It's good to know what tires give good wear and ride results on Hudsons especially at speed.

Also, Tire Speed Rating would be good to know for anyone driving at the speed Walt drives. Some Wide Whitewall tires and cheep tires have speed ratings, in my opinion, are not adaquate for todays highway speeds. That information is also on the tire sidewall.

Not all tires give the same ride and control results. As an example, sorry not about Hudson: When I had my alignment shop there was a Jaguar shop bringing their customers cars in for alignment. There was pretty much every tire brand seen mounted on those Jags. But the Jags that handled best and gave the best ride came with replacement tires the Jags originally came with, Perrilli tires.

That won't work the same with Hudsons. Good thing, the original Hudson tires are no longer available. I can remember Dad had to replace a tire on his 51 Hornet every vacation trip because it would get a bubble. Back in early 1950s he drove at faster speeds than Walt now drives on the highways. The most memorable trip I remember was the speedometer needle stuck at 120 after stopping. Which was probably really somewhere between 100 and 105 MPH actual speed.

Boy, what a duel that would have been if Dad and Walt had met on the road back in the day. Dad never liked to be passed and he would return the favor.

Thanks again Walt for the information.
Lee

[Deleted User]

Lee I hit the wrong key, meant to say 215. I used to race all my buddies back in Waterbury, CT in the old days, 1936 to 1942 when uncle Sam said he needed me, and never got beat. 1936 Terraplane, then a 1937 Terraplane, then a 1938 Hudson 8 and when I got my new 1942 Hudson Super Six, fully loaded 4 door sedan, I took it easy for awhile, 2 months, then went into the Army Air force, B-17 bombers, England for 3 1/2 years, then home married Margaret and started my own garage, selling Hudsons and repairs and here we are today doing the same thing. I raced Midgets and stock cars for 32 years and never got hurt. I built my own cars. Margaret was happy when I said that's it. Today her favorite saying is, Walt you are not on the race track. THOSE WERE THE DAYS. Walt.

ESSX28-1

From an earlier era. Went up in this a few years ago - gotto grab opportunities when they come round!!

Kdancy

Walt, you mentioned Waterbury CT. Did you know any of the guys in the PBS special on WW2? One of the towns they used for the story was Waterbury.

Browniepetersen

We were at a car show on Sunday with Doc Hudson and had a B-17 fly overhead on a glide path for landing. What a sight......

PaulButler

We have an air show over here at the local RAF base just down the road from me.

It's on next week and one of the promised attractions is a B-17 'Sally B'.

Looking forward to that as well as the Spitfire , Lancaster & Hurricane as well.

Only pity is that my '112 is not well enough to make the journey

[Deleted User]

We had a B17 and a B24 here last year giving rides, $75.00, I bought a ticket and we were all lined up to board when I said I,m not getting on that plane till they reverse all 4 engines 3 times. Reason, if they hit the starter the bottom 3 cylinders will blow apart. They did the reverse turns and we all got on, and the pilot calls my name a said will you stand behind us and tell us if we are doing everything correctly. They did all correctly and I told them, good job. Brought back memories of 43 to 45. Walt.

[Deleted User]

No, by reversing the engine the oil is pushed out the exhaust port. Then when it's started a nice big cloud of oil smoke comes out. Once the engine is installed it can not be touched. This is on all radial engines, the B-17 are 9 cylinders Prate and Whitney made in Hartford CT. When tested before take off if it does not hit 1200 RPM's it's pulled. Max is 1800 for take off then 1200 to 1300 for cruising. Boy, do I miss those days. Walt.

brumac

Walt, what outfit were you in? My uncle was a pilot in the 367'th of the 306'th. Bruce

TwinH

Thanks for your service Walt! There are two B-17s next to my place.
This one last flew in 1992 during hurricane Andrew,over a mile with no one on board.
Its now a walk thru 'immersion' experience at fantasyofflight.com/aircraft/worlds-greatest-aircraft-collection/boeing-b-17-flying-fortress.aspx



The other, "Suzy Q" is a future restoration project and part of their 'Golden Hill' tour.

TwinH

They even managed to get this gent back into his ball turret.

[Deleted User]

I was stationed at Kimbolton, England, 60 miles north of London. I was in the 525th squadron , 379th bomb group. Even in the young days it was a job getting in and out of the ball turret especially the bellow turret. Our bomb group got the most awards and we were sent home as the first wave. Margaret and I made a trip back there and the town of kimbolton put up a big stone marker. We were treated like kings. I do not remember any stories about that, as there are many Waterbury's in the New England states. Vermont comes to my mind. Walt.