GET YOUR DEDICATED SNOW TIRES NOW !!!

I just put in a question about this on another forum to a moderator who is much more experienced with TPMS than I am and who bought an Autel device to clone sensors. Yeah, maybe the vehicle ECM can wake up sensors on stored wheels and retrieve information from them.

But if that is what is going on, why would it matter? If one doesn't have sensors on his winter wheels, the warning light is eventually going to come on anyway. If a vehicle ECM is picking up pressure information from cloned sensors on stored wheels, the ECM is going to start picking up pressure information from the sensors on the mounted wheels that have the same ID's shortly after driving away from the stored wheels.

Regardless, it is an interesting question.

 

The "definitive" answer I got from my friend on another forum was essentially "maybe". Here is some of the text from his reply:

Most microchip developers who support TPMS do include the ASK 125 mhz transmitter in their base station (on the vehicle TPMS computer) and matching receivers on the wheel mounted TPMS modules. Base ==> wheel sensors. This is the same as used by the handheld pinging tools.

And of course we have the TSK 315 or 433 mhz transmitter on the wheel sensors sending data back to the vehicle. Wheel sensors ==> Base station.

So a two-way conversation is possible.

The real question is do they make use of the ASK transmitter, and when? Some systems query the wheels on cold start-up. Or if transmission seems to be lost. Or if a sensor is reporting a low pressure situation, the base might ask for verification. All these modes are possible, but whether they are enabled or not is entirely up to the vehicle team.

 

Who is the "vehicle team" in this sentence? Is it the manufacture? Or dealer? Or the owner? Are they configurable on each car, especially on PRIME?

FYI, my old Civic had two distinct warning lights on the dash. One is TPMS malfunction warning light which comes on when TPMS is not functioning correctly such as in case of dead battery in the sensor, or missing sensor. And another is low tire pressure warning light which comes on when TPMS is functioning correctly and the sensor senses lower than threshold tire pressure. For Prius, those two warnings are shared by the same light. It maybe possible, that PRIUS ECU (=base) sends signal to TPMS sensors in wheels to check the TPMS functioning correctly upon turning on the vehicle. If the sensors does not respond to this query, the TPMS light will blink and stay solid. If wheels with sensors are stored near the car but off, it can still respond to this query, thus no light comes on for the first ~20 miles or so, after which, car realizes that there are no sensors on the wheel thus initiating the blinking lights and solid light routine.

 

I'm pretty sure that his use of "vehicle team" represents those who designed and engineered the specifics of a vehicle before it was manufactured. My forum moderator friend who came up this verbiage is a design engineer whose work spans electrical, mechanical and software.

 

OK, this is not for PRIME, not even regular Prius. They are dedicated snow tires, Michelin Latitude Xice Xi2 235/65R18 mounted and balanced on Nissan OEM 18" alloy wheels with working OEM TPMS for my wife's 4WD Pathfinder Hybrid. Total cost for tires, wheels, TPMS including shipping, installation, and tax for $881, after discounts and rebates. I did well.

 

A very good suggestion if tires are mounted on separate wheels and if you can DIY the change over. For my first two cars with winters, to save money I did not buy separate wheels, thus winter change over meant taking tires with the car to a tire shop. Many of our local tire shops offer free winter change over with free storage of tires if I buy set of tires there. However, this set-up sometimes did not work to beat the first snowstorm of the season. Of course, taking off the snow tire has been a hit and miss event also. We have had more than 10 inches of snow dumped well into April or even early May, after the changeover.

 

I like to swap over slightly in advance of a time when ambient temps are dipping to or below 7C. This is the temp below which winter tires have traction advantage. Also, I like to wash and dry the tires coming off; prefer to do this on a nice afternoon.

 

That is ideal, but budgetary constraints come into play. A set of snow tires on steel rims was going to cost twice that and I'd have no TPMS unless I ponied up an additional $200. Plus where I live, I may run into snow 10 days out of the year, I dont need to optimize for that condition

I just went with all seasons, which are a HUGE upgrade from the fuel saver tires in all conditions (dry, wet, and I will assume snow).

These new tires (BFG Advantage T/A sport 195/65R15 T) where phenomenal. I could easily take corners 20% faster. 90deg turns at 25 vs 20mph. I haven't pushed them in the dry yet, but I have noticed they at least go to where my old tires would "sing" (not screech) without making a sound. I will test them later.

I used to take my last car out to the track and I'd never know if it was going to rain that weekend so I always put all- seasons on it. I'd honestly like to track this Prius if I wasnt worried about how hard it would be on a car not designed for that. My previous track cars were all meant for that kind of driving.

 

That's very true. I started using 303 Aerospace Protectant Sprays after change-over wash. Don't know if it has any effect on longevity of the rubber as claimed by some on YouTube, but it makes tire shine while being stored.

 

I wax the rims, both the OEM alloys and the steel winter tire rims.

 

This is common wisdom, but I disagree. My all-season tires have more grip than my Blizzaks far below 7C. It was probably true in the past, but modern all-season rubber is pretty good. I haven't run these all-seasons much below freezing, but on previous cars there's no noticeable degradation in performance if the roads are dry, probably down to -10 or -20C.

Around here, infrequent snow storms extend the season into October and April. We had some snow two weeks ago, and we'll get a little more this week. But it's possible that it could be dry and sunny after that until the end of November. So it's hard to decide when to put on and take off the snow tires. And the Blizzaks I have do seem to wear quickly on dry pavement.

 

If I really want to minimize the snow tire wear, I would swap winter and all season a day before and day or two after each snow storm. We have snow 4-5 times/season that covers the road surface maybe total of 2 weeks out of entire winter. But that would be too much hassle. Leaving them on from Nov to April seem to work for me. I just checked the tread on my Xice I wore one season (Nov-Apr) ~5K miles. They have lost ~1/32 inch of tread from new. If the rate hold steady and if I change them at 6/32, I have 3 more seasons, meaning total of 4 seasons. That's about all I can expect from snow tires. Total 20K miles. Xice have 40K tread warranty, but that's if I wear them down to 2/32, which is not safe tread depth for winter tires anyway.

 

Snow tire "early adopters" might be owners buying for the first year, trying to avoid the last-minute rush, and/or tires sold out.

A few extra weeks with snow tires on isn't the end of the world; don't get all defensive, lol. I'm DIY'ing the swap, but I still prefer a bit early, again, just for my comfort.

 

Yeah, that warranty is nonsense. You have to wear them down to 2/32, but you're only allowed to use them during the winter months (defined in the warranty brochure). I'd be OK with running them for one summer just to "use up" the rest of the tread, but that would void the warranty.

I should get a garage with a lift, then I could have "dry day" X-ice tires that I run down to 2/32, and "snow day" X-ice tires that I keep a reasonable amount of tread on. I wonder how long it would take to make up the cost of a lift and another set of rims with the warranty benefit? Probably a lifetime.

Maybe someone should start a Nascar-speed tire shop where you can stop in for a 1 minute changeover before and after every snow day.

My Blizzaks lost a lot more than 1/32 in less than 5000 miles last season, with most of the wear being on the front. I'll have to get them out of the attic and measure the tread. I'll rotate those to the back this year, so I should be able to get about 2-4 seasons total out of them.

 

Poor man's lift: a floor jack and four safety stands.

 

I do mo own wheel swaps with a floor jack, but it takes too long to do before and after every snowstorm. I'd probably want centerlock wheels too.

 

Humm, I've never tried that before. That may work for me. After I am done for the last winter season with 6/32 or less left, I will just keep driving them one summer. That will give me at least one summer I don't have to wear my all season. Thanks for the idea.