View Single Post
Old 04-25-2022, 12:53 PM   #24 (permalink)
Master EcoModder
Join Date: Jan 2012
Location: MI, USA
Posts: 571

92 Camry - '92 Toyota Camry LE
Team Toyota
90 day: 26.81 mpg (US)

97 Corolla - '97 Toyota Corolla DX
Team Toyota
90 day: 30.1 mpg (US)

Red F250 - '95 Ford F250 XLT
90 day: 20.34 mpg (US)

Matrix - '04 Toyota Matrix XR
90 day: 31.86 mpg (US)

White Prius - '06 Toyota Prius Base
90 day: 48.54 mpg (US)
Thanks: 8
Thanked 73 Times in 50 Posts
I'll have to check the hybrid battery health once I find my scangauge or buy a 2nd one. I'm guessing the battery is doing alright, I'm pretty sure it's not about to fail since the bar graph indicator rarely moves.


I've been running max side wall pressure on tires for at least 170k miles on different vehicles, cars, trucks, etc. My dad's a mechanic, he ALWAYS uses max sidewall pressure for his vehicles as well. We both have never had bad tread wear unless the vehicle's alignment was bad. The low end cheap tires I've had busted belts on a couple of times, but never had a problem with a quality brand name tire. If it say's made in China, it might be a "China bomb" tire so lower pressure might be best for those.

If you recall the firestone recall back in the 90's, the issue was partially caused from under inflated tires by Ford, I wish there was a study done with running the tires at higher pressure, max side wall, etc to see if it effected failure rate since the tires did have a manufacturing issue as well. My dad said one of the training sessions he went to had a rep from one of the tire manufactures, I can't remember the exact figure, but something like 10% under max side wall pressure the tire manufacturer counts as under inflated.

Publicly, Firestone argued that Ford's recommended 26 psi inflation pressure was too low and should have been 30 psi. In addition Firestone argued that the Explorer was abnormally dangerous and prone to rollovers in the event of a tire failure, leading to more injuries and fatalities.

Ford argued that the Explorer was no more dangerous than any other SUV and that the accident rate for Explorers with Goodyear tires was far lower than for Explorers with Firestone tires. Ford also argued that there was something wrong with the design of Firestone tires and with the manufacturing of those tires with Benzene.

At the few different places dad worked, most of the auto shops like to inflate the tires to 35-40psi at least in our area even if the car suggests 26psi.

Anyway, I'm not trying to twist your arm to running higher pressure, just putting out what I know/understand on tires. If I was in your situation, I'd just run 40psi front and rear. It's within the 10% max side wall range, but isn't super high to cause tire failure. The tires are rated with a max sidewall pressure, and there's a built in safety margin. Most likely the tires can handle twice the sidewall pressure or more before they blow up.

Just like the firefighter air tanks, the ones I use are rated at 4500psi, hydro testing is done at around 10k psi, and at the factory they are tested to failure which I think was 15k psi. The fire fighter tank we use for PCP air rifles, and my dad found that there's an adapter to adapt the tank to air up car tires. We used it once and was able to fill up all 4 tires on a car off it that had 3 flat tires and one low. We still had some pressure left (2200psi if I remember right). Very handy for the kind of stuff we do. A normal air tank at 100psi can do about 1 to 1.5 tires when completely flat.

I've always went for somewhat cheap but name brand tires. My corolla's tires were nothing special, rated for 50k miles, 44psi max sidewall, and they were budget tires, not LLR tires. I put about 80k miles on them and the tire wasn't to the wear bars yet. I did drive on winter tires during winter for a year or two so I'm not sure how many miles the tires really have but should be over the 50k rating. If I remember right they were like $55 per tire back around 2013. I haven't dove the car quite a while, the metal that the gas tank straps bolt to rusted out. I basically did no maintenance on the car, it's truly a beater before I even got it. Front end has been clunking and making noise since I've owned it, hasn't changed at all in the 80k miles I drove it lol. I think it had a tie rod a little sloppy on the driver's side and the strut mount was the main source of all the noise.

I kind of wish I could run across a prius that's super cheap with a bad engine/trans, I think it would be interesting to swap in a 7a-fe corolla engine and trans and work out the CV axles to fit the prius. I know that engine does real good for mpg would be interesting to see how it does with a car that's more areo but heavier. At the same time, it would be interesting to transplant the prius system into a 93-97 corolla and see what kind of mpg it gets. I guess just looking at a 2007 Camry's mpg should be an alright reference for hybrid vs non-hybrid for the same car. Hybrid mpg is 34mpg, non-hybrid (same engine but "normal" built) 31mpg for highway. Looks like around 10% difference. My corolla got 38-44mpg, so with the prius setup in it, I'd guess it would get around 45-50mpg, pretty much the same as in a prius, at least for the one I have. I guess that suggests the overall areo drag should be similar for the smaller corolla (with my minor mods) vs the larger prius.

I'll have to brainstorm some ideas for the Prius. I think the style of testing I was doing is good enough to get an idea of mpg with out needing to go 100's of miles, I'm sure it's far from perfect though.
  Reply With Quote