Probably not going to convince the mpg nannies. Running max pressure unloaded will wear the tire unevenly. The marginal increase in economy is not worth the decreased ride quality and tire life.
Gen2 owners running Toyota recommended tire pressures were reporting uneven wear back in the day. Outside edges, IIRC, which would mean underinflation. Overinflation leads to faster central wear. Tread depth should checked regularly, and across the entire tire width. Higher pressures makes the sidewall stiffer. That leads to less tread squirm, which can mean less wear to the tire. Higher pressure could lead to less wet traction though. Ride quality is like seat comfort; subjective. I generally find the factory pressures 'squishy'. I prefer tighter suspensions.
Tires have certainly made significant advancements in the last two decades. The Toyos that come with the 23 are a no doubt a considerable improvement from the "fuel saver" Goodyears that were fitted on earlier models, which were known to only last 30-40k miles. It seems as though the older tires were primarily designed to maximize fuel economy? As for tire pressures, I have Toyo AT3s on my FJ, which cost around $340 each. Consequently, I am meticulous about checking my tire pressures and ensuring that I rotate them regularly. In the 4x4 community, we perform the "chalk test," where we draw a chalk line across the tire and drive on it briefly. We then check the line for wear and adjust the pressure accordingly to ensure even wear. I plan to conduct this test on the Prius once the weather clears up. With proper care, I expect these Toyos to last a minimum of 65k miles since they are rated 300 for treadwear. After driving the car for a few hundred miles and tossing it around a bit, I can confidently say that there is little to no squirm or roll in these tires at their stock pressures. I've used many premium tires in the past, including Continentals, Pirellis, and Falkens, mostly for sports cars, and these Toyos feel just as firm as you could expect considering the profile. At the moment, I don't feel any need to change the pressures due to handling issues, but the chalk test will help get the most life out of them. Only time will tell if they meet my mileage expectations, if they do I would definitely consider rebuying them if available.
What if one simply removes the styrofoam then cut the left and right side items so they result in a ‘L’ shape…well more like a ‘U’ shape in a manner of speaking. That way you have the long (front of car to back) length on each side to form a surface for the floor ‘top’ canvas to rest on. The part of the foam that goes side to side (wheel to wheel) could be X inches long depending on where you cut off the excess not wanted/needed to creat a stable ‘U’ shape (say 6”). Then you would have the entire center empty to put things on to use that extra space. Not owning one nor seeing one this idea could be full of holes. Plus that canvas floor cover is I think folding thus it might just bend in the middle downward and not remain flat. Still it seems a waste of space not to get rid of most of that foam unless it does indeed increase sound levels too much though even then one would think you could add a rubber matt on that floor to deaden the road sound a bit.
I've heard of factory tires having less starting tread than the retail models. This is likely to help with fuel economy testing. The foam insert for the raised floor isn't like other such inserts that only have spots specific to jacks and repair kits. It has open storage compartments in addition to the spots for the tools.
Here's some pics from reddit about the foam inserts. Code: https://www.reddit.com/r/prius/comments/11xnhz6/followup_2023_xle_pics_of_storage_area_in/?context=3
Some photos are floating around here. @hyhi was thinking the foam tray was like that in other cars, including Toyotas, in which there isn't bins for general storage. Except for slots for a jack and tire repair kit, the empty space is entirely taken up by foam.
Looking at the reddit photos, it seems like one could get a LOT more useable cargo space if a lower floor could be designed that would still protect the orange cable. Seems ripe for an aftermarket provider to come up with something to do just that.
I will be tackling this once we get a streak of some good weather. I'd still like to add a spare and I know I can free up some more space back there. I have no qualms about getting rid of the foam. The storage area is literally full with two carry on size bags as it is...
I agree. Strange design choice Toyota made there. You would think that they would want to advertise the most cargo space possible?!
Toyota already did this; the LE has 3.5 more cubic feet of cargo space. It doesn't have the foam tray and raised deck. There is just a short tray with spaces for the repair kit and tools over the floor. I haven't seen photos of it, but the manual has illustrations under the fixing a flat section. Markets that get a spare tire place that in a tray that replaces the storage one under the deck.
Nice...forgot about that! Another reason why I'd get the LE. It would be nice to see some photos of it.
Very interesting. I did some digging. It looks like the foam, cover, and maybe the battery cover are different. Here's an LE trunk And heres Limited.
My friend in parts gave me the PNs for the floor panels and foams. We can't verify which is which right now because the vehicle is so new but they list them as "with" and "without" spare. It would cost upwards of $1000 to buy the parts to swap right now but I bet this number changes in a few months.
pretty sure tht's how much it cost in gen 4. a lot of people did their own custom thing because of cost. there's always salvage down the road
Just because I was curious I went and pulled the foams out and placed the cover down on the lower level. Close but no cigar. The front edges don't match the profile of the inner fenderwell so it won't sit all the way down, and its a little short of the rear. I think it could be modified to work but you will still need to add some reinforcing under since it will just cave in. The difference in space without the foam is quite substantial but alas no spare under there either.
On another note. When I was in there I observed that it looks like it will be very easy to run some wires to the JBL amp which is located under the driver seat for my subwoofer input.
Foam padding might be all you need to protect any wires, if the floor not being completely flat is fine.