Tire pressure - tire wear

3-4 psi increase is what I get after my normal commute of 19 miles drive with gentle braking and acceleration on rural highway with chip seal surface. Internal tire air temperature rises 10-20F for this drive. If you are talking 1 mile drive to gas station, there should not be much change in temperature thus not much changes in psi. BTW, if you do topping off air in your tire often enough, investing in portable air compressor maybe worth thinking about. Cheap ones are only ~$10, but I would recommend getting more powerful one for quick fill. I use ViAir 70P (only $32 at amazon). 70P Portable Compressor | VIAIR One thing about ViAir P70 is that it is small and least expensive model of portable compressor in ViAIr line-up, but it is still very powerful for regular passenger car tires. It draws 15A, but comes only with cigarette lighter plug. If you use it on Prius (or many other passenger cars), it will blow fuse (only 10A). You do need to get alligator clip extension to cigarette lighter plug so that you can directly connect to 12V battery.

 

You are welcome. I didn't realize you are in Germany. I am not sure ViAir model is sold there, but there should be similar ones there I am sure.

 

@Oddfodder, if you over-inflate a bit when at the gas station, then you can adjust the pressures downwards, first thing in the morning at home. I would recommend to always do that, and have a simple/accurate gauge you always use.

With 215/45R17 tires, using 42/40 (front/rear) is a very firm ride. I did that for the first few months, perhaps a year, with our 2010 Touring (similar tires), but then with some reading, thinking, experimentation, settled on 36 psi (for all four, for simplicity) as a max. I'll let it slip lower, down to say 33 before making any adjustment.

A concern I have, beyond ride comfort, is that low profile tires (like the 17's on Prius) and high pressures, may wear out the car's shocks and bearings prematurely. Even at recommended pressures the tires are quite firm, and I think tire flexing is part of the car's suspension system, takes some of the shock when the car goes over speed bumps or pot holes. I slow to a dead-crawl over speed bumps, hate them...

I used to add air at gas station; here Chevron still has free air. But I found in recent years at several stations, it seemed like their air was barely strong enough to raise pressures. During the same time I acquired a simple/basic floor-standing bicycle pump, very simple. It has some kwirks, but I've learned the best methods for using it. It's designed for bicycle tires, and though somewhat labourious, is very simple and effective with car tires. I've even brought car tires back up to pressure after having a flat tire and plug-repairing them.

 

I'd just remind folks to be sure to select a regular sized floor-standing bicycle pump.

Small diameter pumps for higher pressure bike tires will need too many strokes for a car tire. The lower pressure / higher volume pumps may require too much pumping force for smaller or less able-bodied people, though stronger folks might well prefer the quicker results.

I live just three blocks from the nearest gas station, yet still find the bike pump quicker and easier. I do have a 12V pump too, but counting the time needed to tightly coil the cord and hose back into their tight stowage spaces, the manual bike pump is still quicker and easier.

 

Yeah the pump I'm using is just a cheapy, but conventional size, not compact. If it ever fails I see some nice ones for around $40~60 at local bike specialty stores. Maybe I'm a closet survivalist, but simple, manual power often wins the race, especially with the convenience factor.

 

Or you can use one of those I often use on my car. No coil of cord, no long hose. You just need charged battery. It's got be easier than bike pump, IMO. and at $20 maybe cheaper than bike pump. (battery not included!)
Ryobi 18-Volt ONE+ Cordless Power Inflator (Tool-Only)-P737 - The Home Depot

 

At least you mentioned no battery. Battery cost more than the pump itself, and that's w/o buying the charger for it also.

 

Yeah, that's true. But with Ryobi ONE+, Home Depot has sale on kits all the time. It is cheaper to buy tools with charger and battery as set. I have multiple kits with multiple batteries and chargers. Two impact wrenches, two flashlights, two shop vacs, one each in car or garage, and other one at home or office.

 

After all that, probably $300 would be the price. Some will rather stick to a $20 bike pump in their apt.

 

Whaaaat, you mean you don't need a cordless drill and/or rechargeable flashlight if you live in apt. I can't live without them.

 

$20 cordless drill + $10 usb battery charger w/flash light combo = $30

 

OK, I can live with that. But since I also needed cordless circular saw and brad nailer and reciprocating saw, I was served better with ONE+ kits.

 

I don't get these battery powered everything; think they're a scourge. They're taking over in our local hardware flyers, oh well: we progress.

 

This is the one I keep in the back of my car from Harbor Freight. I got it with one of their 20% off coupons so it cost me around $28.
Works great and is a high volume unit so it will fill pretty quickly.

12V 100 PSI High Volume Air Compressor

 

... A fully serviceable bike pump at Walmart is no more than $20. The slightly shorter one staying in my car fulltime was $10 on sale, though it is less robust and now needs an added retaining screw. A project for this weekend.

What good is it without the battery? Besides as a fishing line sinker, of course.

And if I throw it under the trunk floor with the spare tire, how many years will the battery hold a usable charge?

 

My first electric screwdriver has been through two generations of batteries, and is once again a fishing line sinker until I can find a third round. With Sears going under, I'm not yet sure any are left. Dad has a newer electric screwdriver/drill, and its first round of batteries are also nearing the end of their life.

Meanwhile, my manual screwdrivers a decade older are still working just fine. As are dad's. And step-granddad's too, 56 years after he passed.

Even my grandpa's electric (corded, not battery) electric drill is still running quite well, 32 years after he passed. And he probably had it longer than I have.

 

Yeah local ad fliers: page after page after page of battery powered power tools, often bundles. I keep thinking there's something wrong with this picture. I don't think they have the same oomph, and the upkeep is much more of a pain. And the prices...

 

Hand tools are fine for many occasion, especially as a backup for an emergency, but battery operated power tools are lifesaver in some occasion, certainly a timesavor for most. If simpler manual tools can do everything all the time, I would have only a bike pump and riding a bike for all of my transportation needs. No driving Prius.