Whoops! Thanks. I also used 450 instead of 460 for the R-F conversion.
1 Like
Old philosophy.
Correct. Lower (handling) pressures in summer, higher penetrating pressures in winter.
1 Like
Because in temperate climate zones (Australia or mid latitudes North America, it is rarely 68F for long periods at a time.
If I need to replace my tires, with something I can use on dry and wet pavement, and occasionally on snow and more occasionally on ice or mud, are there better choices than the Michelin Defender 245 55R19 103H LTX M/S BW SL tires I bought last time? Iām willing to pay a bit extra for durability and quietness, and I want the tire to be common enough to have some chance of finding it in stock if one needs replacement. They should be bidirectional so I can rotate again with a full size spare. Iāll ask the tire store I trust, but Iād welcome other opinions. I drive conservatively, almost never over 70 mph (but Iāve twice driven on an 80 mph highway and might again) and live near DC, in a warm humid climate. The tire store carries Michelin, BFGoodrich, Uniroyal, Firestone, Bridgestone, Continental, Goodyear, Kelly, and Dunlop, and unspecified other brands. The Venza nominally weighs 4045 pounds, and can carry up to 1225 pounds. I donāt tow a trailer.
The reviews and category comparison charts at Tire Rackās web site will likely be helpful here.
2 Likes
I still donāt understand why you want to waste money on new spare . All you need is a spare the right diameter to get you to a tire shop. 5 tire rotation is a thing of the past .
2 Likes
Dry rot. He doesnāt have a dedicated spare tire; all five tires have been exposed to weather and sunlight.
I agree. Get a spare, leave it in the trunk.
1 Like
The tire store should have a cheap tire the right size or even a used one with decent tread .
1 Like
+1
I donāt pay much attention to the user ratings, but the tire tests are well worth looking at.
2 Likes
I used to, but then I realized, they might not even have the correct pressures set!
1 Like
I donāt want snow tires - I want the same tires on the car all the time, and if I remember right, snow tires have much lower tread lifetimes. Studded tires arenāt legal where I live and drive.
Two possible issues are the 103H load & speed rating.
The vehicle is rated (GAVR) as having up to 3090 pounds on the front axle, according to the door jamb label (less on the rear axle). In symmetric situations that would be 1545 pounds / front tire. The 103 appears to mean that the tires can accept up to 1929 pounds each. But - they must take more on turns. Or is that already taken into account in the GAWR or ā103ā ratings?
The H rating appears to mean they can go up to 130 mph. Even if I drive on the 80 mph highway, and drift 5 mph over that, that is only 85 mph. OTOH, DC is pretty hot, and if I were to drive to Florida, it could get hotter. Maybe a higher speed rating means it can take the heat better?
says
The reduced tread life sounds bad. So far the vehicle has so far handled and braked very well, under all conditions since I bought them in November 2018 (and they were made in 2018), with these tires - maybe because I drive conservatively, but thatās what I need. OTOH, the time limit and puncure problems may be an issue before tread life on these 70,000 mile/6 year warranted tread life tires, for me.
They were pretty expensive tires. That was my decision. The tire store gave me alternate options, including cheaper Michelin Defender M/S tires. I asked them what would be most durable, and they guessed these - which was of course their most expensive option. 
Tire Rack, with my selections, recommends Continental CrossContact LX25, Pirelli Scorpion WeatherActive, and Pirelli Scorpion AS Plus 3. They do not recommend any Michelin Tires, no matter what I have tried putting into the tire decision guide. But if I bypass the decision guide, they do list some Michelin tires, including some rated at 107H and 103H.
Consumer Reports appears to like the updated M/S2 version of the tires fairly well for mixed driving conditions. And this guy
who is looking at the tread pattern, likes them too.
It will be a while before I can get to the tire store. So I swapped the tire with my full size same type spare. The leaking tire might have two embedded metal objects - but one of them - quite large - might be a patch they put in to repair an earlier puncture. I will have to ask the tire store. The other might be a nail - I will have to ask again.
Iām not sure where these metal puncturing objects are coming from. I donāt drive on construction sites. And I try to avoid driving over road debris, but I must be failing at that.
Is that really true for AWD (or 4WD) vehicles? Tire stores and car companies often claim using tires with different wear amounts, or different tread patterns, can destroy AWD and 4WD systems. But they donāt say how fast. In particular, assume I may have to drive a few hundred miles or more before getting to that tire store, as I clearly stated. I know from past experience that using a donut spare on such trips probably damaged a 4WD vehicle - but I admit there is a big difference between a donut spare and a full size tire with a different amount of wear, and maybe a different tread pattern.
I do admit that the tire store I trust thought I should follow car manufacturer suggestions, which did not include 5 tire rotation. Toyota said to swap the front and rear tires on the same side. They donāt even say to swap left with right.
For crying out loud! Our Subaru Outback only comes with a temporary spare and the people who made it expect the vehicle to go places that are not paved super highways. many posters here donāt do 5 tire rotation, your manual doesnāt say to do it .
I am done and out of here. Just do what ever you want.
1 Like
As you well know, I embrace the past for many things (CRT tube TVs, no āDaylight savingā, or social media, etc), but even I know that, with the prevalence of radial tires, and more recently directional radials, 5-wheel and/or cross rotation are no longer necessary, and even discouraged, by vehicle and tire mfgs.
Iāve truncated the rest of the post to save space., but I will address many issues raised in the resulting verbiage.
First, go find the vehicle tire placard. Itās a yellow sticker in the doorframe. It will tell you the original tire size and the specified pressure for that size. Use that size as not only will the speedometer read correctly, but the vehicleās handling was designed around that size.
As far as treadwear goes, the UTQG treadwear rating is what to look at - not the speed rating. There are plenty of exceptions to what you posted and the UTQG is a much, much better indicator.
Ignore the Load Raing. That is there to help car designers choose the right size. Donāt second guess their choice.
And lastly, you are spending way too much effort here. Tire Rack gave you some good choices. Select one!
6 Likes
Agreed.
I did however Capri, something that I feel most folks on here, and on other automotive sites, donāt do and didnāt understand:
Using the Front and Rear āGAWRā ratings on my 2010 Honda, by dividing each of those figures in half, I was able to determine, consulting the tables at tirepressure dot org, that, at 32psi cold, the OE size tires supported 111% of the front gross axle, and 129% of the rear gross axle load. āGrossā meaning the maximum loads those ends of the car would ever be asked to carry. (Accord being a basic front-wheel-dr family sedan, it has a significant forward weight bias).
I could, in theory, lower the rear cold pressures 1-2psi, to ābalanceā out the contact patches a little, but I think Honda already figured that out, by specifying slightly narrower gauge coil springs in back than in the front. I measured their thicknesses several years ago, so I know that for a fact.
Summarily, there is no real reason to inflate the tires on this Accord more than 1psi over, for winter driving, or to allow for potential tire gauge error.
I conducted the same research for my friendās 2018 Tucson, and found that the 35psi specified for the OE tires on that crossover to carry, front and rear respectively, 125 and 130% of GAWR. The steering is direct but very light.
(I road tested the Tucson, briefly, at 33psi cold whilst they were away and I babysat the keys, and the steering definitely firmed up, felt heavier and more car-like, with little increase in body lean.). They are currently maintained at the OE 35psi door pressures, since itās not my vehicle.
Excuse me Capri, while I don my helmet in anticipation of inward-bound flackā¦!
Most modern cars and trucks do not come with a full size spare. Just like my Venza did. Some of them donāt even come with that - just a can of tire sealant, which many sources say isnāt always enough to make a flat tire work. It saves space and weight, and the weight savings give you a better MPG, but AFAICT, it makes no sense for people who will drive far from places where you could buy replacement tire(s). I guess the change occurred because āSUVā to most people no longer means a vehicle with lots of road clearance and sturdy truck parts that you could take on excursion into remote wilderness, but now often means a city car or minivan with more space for people and groceries than a sedan. The damage I did to my old Ranger differentials shows what can happen as a result, if you are actually still drive into remote wilderness locations - or even take long highway through the middle of nowhere, far from open tire stores, and get a flat.
Which is why I and many other people replace the compact spare - or donut spare - or whatever they call it, with a full size spare.
And also why I, for better or worse, switched to bidirectional tires - so the full size spare could work well on either side. But maybe that wasnāt needed, and maybe I didnāt need to buy a full size tire and wheel of exactly the same type as the regular tires and wheels, like I did.
I guess if the damage came from the two wheels rotating at much different speeds for a long drive (because a compact spare might be, say, 60% of the diameter of a regular tire, perhaps roughly 20 times the height difference between worn and unworn full size tires), one could without much harm drive roughly 20 times longer on a full size spare than the 30 miles many sources say is the limit for driving a compact spare without doing much harm to my differentials? Do I have that right?
OK, between you, other people, and my tire store, I guess I will accept that 5 tire rotation was a bad idea, or at least more trouble than it was worth. And maybe I should switch back to unidirectional tires - if they really are better?
Also, instead of replacing the spare tire now with whatever new tire types I replace the regular tires with, I could just use one of the current regular tires - preferably one that doesnāt have any puncture repairs.
I guess my assumption that I need to take high speed turns into account (where people often say all the weight effectively transfers to one side of the vehicle) in the load ratings doesnāt apply to my conservative driving style. So I can simply trust that tire stores know what they are doing on load ratings. Of course the overland community, which drives crazy, and the racing community, which drives equally crazy, maybe should boost the required load ratings, but thatās not me. My idea of off-road is just a driveway, or a dirt road or boat access road that rain has turned into mud, or the parking spot in a campgrounds, not a creek bed or mountain peak, like you see in Jeep commercials. And I donāt race, on road or off-road.
My Vette came with Run-flats. Within a month after I bought the car I replaced them with NON run-flats. If I get a flat (which is extremely rare), Iāll call a tow-truck.
1 Like
You trust the vehicle manufacturer to know what they are doing. This is not the 50&60s when 14 inch diameter rims/tire were chosen for looks and two ply tires were OEM because they were cheaper.
The load capacity and inflation requirements are researched by the engineers.
Do you review your own X-rays to see if the radiologist made an error? I donāt even when I was surprised that the CAT scan showed appendicitis. Nor did I instruct the surgeon on the surgical technique to use, nor the anesthesiologist on the gas mix used to put me under.