I have a 1967 Cutlass 330 2bbl. I'm going to be running SSII 14"/7" wheels with 225/70-R14 Hankook tires.
Can anyone give me a "ballpark" psi to start with for these tires?

 

I run mine at 32-33 PSI.

Pat

 

I run 30#s in my fronts.

 

Modern radials are designed to run in the 32-35 psi range. That's where I run mine.

 

x2 -

 

That's under max load of around 1753#'s

 

 

BFG P225-70-15 load/max tire pressure rating @1753#s max air pressure to 35psi. If I understand tire pressure correctly, if your not at max load, you should not be at max pressure.

 

Not true. By that logic, you should let air out of the tires every time you offload passengers or luggage from the car. Tire temp causes more variation than that anyway.

 

That's not necessarily true... The tire load is part of the tire build spec with a max pressure for the load, but there is no requirement to be at the max pressure unless you know you may be near or at the max load... the pressure is basically just a standard applied to the load...

"A tire's maximum load is the most weight the tire is designed to carry. Since a tire's load carrying capacity is related to the tire's size and how much inflation pressure is actually used, maximum loads are rated with the tire inflated to an industry assigned inflation pressure"

Read more here: http://www.tirerack.com/tires/tirete...jsp?techid=195

 

I agree, however if your inflating to the max pressure of 35 and your not running near the max weight, your tire is over inflated. Then compound the issue with the pressure increase of a hot tire... you get drivability issues and abnormal wear.

 

Thanks guys I got my answer!

 

But ... but ... we're not finished!

 

Or under inflating the tires that's why they have TPMS mandated requirements on vehicles today.

 

They have those systems today because apparently the public does not know how to properly operate and air pressure gauge or is to lazy to do so. Now they are going to mandate back up cameras because people don't know how to use mirrors and possibly evolution must have limited the travel of some peoples necks which prevents them from looking out the back of the vehicle.

 

Fronts 34 lbs & backs 31 lbs is a good ball park.


If you want to do it right put a chalk mark across each tire & roll the car forward. If the chalk mark disappears from the tire evenly you are correctly inflated. If you have chalk only removed from the center portion you are over inflated.

 

TPMS is mandated because Congress had to look like it was doing SOMETHING in response to the Ford Explorer/Firestone rollover debacle. The real cause was that owners were too stupid/lazy to check tire pressure. Don't expect an elected official to tell the constituents that it's their fault, however.

Same thing is coming with backup cameras next year. People are too fat/lazy to look over their shoulder or check behind the vehicle when backing up. One kid on a trike gets run over and it's the manufacturers' fault for not putting these system in.

 

I am -- This issue can can go on foreverrrrrrr and we will agree to disagree...

 

If all these features are supposed to help i.e. tpms, cams, collision adv. Than we need auto engage turn signals when the wheels are turned.

But when the self drive units arrive, we won't have to worry about all of this!

Pat

 

I keep wondering how anyone who's ever used a Microsoft product can think software is infallible.

Also, an interesting juxtaposition of articles in the Washington Post a week ago. On the same day that the White House called for more self-driving cars for "safety" reasons, there was an article quoting the FAA as saying that airliner pilot competency was declining due to increasing use of autopilot. Keep in mind that airline pilots are MUCH better trained and tested than drivers.

Be afraid. Be very afraid.

 

To 69 442 rag top: To much info gets me CONFUSED, duh!!!

 

"Than we need auto engage turn signals when the wheels are turned."

My GF truck has an annoying alarm that sounds if you cross a line in the road without using your signal.

It's the Nanny State taking control rather than making people responsible for their actions behind the wheel of a two ton killing machine.

 

You don't even want to get into powerplant operation. Both fossil and nuclear require the things be operated in full automatic mode as much as possible for efficiency, then when the shyt hits the fan you have a control room operator who hasn't any idea what to do to regain control of his equipment. Seen it more than once and have had to take control away from operators when they freeze. Got scolded a couple times so I said fine, let 'em drive the thing right into the ditch.


Unfortunately that may not be an option on a self-driving car.


Back to OT, with radials 30 psi for better ride, 35 (or up to 40 on my pickup) for better fuel mileage.

 

I don't think max load vs running the car empty would make any significant difference on tire wear when the tires are at recommended pressure.

It is not in an automaker's interest to make a self-driving car. The first time it wrecks, the fault will be on the automaker, not the driver. Anyone who thinks a self driving car would be infallible is so stupid they ought to never be trusted with anything; it WILL happen. Making an automobile that is self-guided is such an expense that, coupled with the liability for every wreck it causes, it makes no business sense to do so.

This is why you see tech companies, which are usually clueless about real world business and manufacturing, making these things, and not car companies.

All "assists": cruise control, traction control, ABS, adaptive or laser cruise, all around cameras, lane departure warnings, blind spot monitors; they're all assists; they don't take responsibility (and liability.)