Tire size?

[Pyral]

Well if the door says 225 then that's what it had.

My door says 225, but my window sticker says 265. Both the VINs match, so IDK whats going on there. I wouldn't be surprised if dealers did upgrade wheels, but I doubt it was widespread. My theory is that if your 4runner trim didn't come standard with upgraded wheels then you got a 225 sticker regardless of options.

Okay upon further checking I can only find limited models with the 265 tire on the door sticker.

 

[Option01]

My door says 225, but my window sticker says 265. Both the VINs match, so IDK whats going on there. I wouldn't be surprised if dealers did upgrade wheels, but I doubt it was widespread. My theory is that if your 4runner trim didn't come standard with upgraded wheels then you got a 225 sticker regardless of options.

Okay upon further checking I can only find limited models with the 265 tire on the door sticker.

That’s my hypothesis too. Basically, models that only came with the 265 tire got that listed on the door sticker but for models that came with either size based on option packages, my guess is that those all had the 225 size listed on the sticker.

The reason that I’m even worried about it is that I’m trying to figure out how far off my speedometer is with my 33” tires since I don’t know if the speedo was setup for 225 tires (door sticker) or 265 (what I think was equipped at the time of purchase).

 

[pluton]

The reason that I’m even worried about it is that I’m trying to figure out how far off my speedometer is with my 33” tires since I don’t know if the speedo was setup for 225 tires (door sticker) or 265 (what I think was equipped at the time of purchase).

1. As with with the axle ratio code numbers, the door sticker may not be accurate on the wheel/tire size. One of the colorful quirks of Toyota.
2. Find a friend that has a hand held GPS receiver (or smartphone with GPS app) that shows speed in MPH, go for a drive on the highway and check against the GPS. GPS speed isn't accurate at slow speeds, so go 30MPH or above. 60MPH is fine.

 

[gtojimbo]

My door says 225, but my window sticker says 265. Both the VINs match, so IDK whats going on there. I wouldn't be surprised if dealers did upgrade wheels, but I doubt it was widespread. My theory is that if your 4runner trim didn't come standard with upgraded wheels then you got a 225 sticker regardless of options.

Okay upon further checking I can only find limited models with the 265 tire on the door sticker.

yea, that makes sense!

 

[Option01]

1. As with with the axle ratio code numbers, the door sticker may not be accurate on the wheel/tire size. One of the colorful quirks of Toyota.
2. Find a friend that has a hand held GPS receiver (or smartphone with GPS app) that shows speed in MPH, go for a drive on the highway and check against the GPS. GPS speed isn't accurate at slow speeds, so go 30MPH or above. 60MPH is fine.

Thanks! My wife and I both installed the Speedometer app on our iphones and took the 4runner onto the freeway. The results were really strange though because both phones showed 3 mph faster than the 4runner's speedo at all speeds ranging from 40-80 mph. I thought I would be further off with 285/75R/16 tires and that the difference would increase as the speed increased. Perhaps 35 psi is not enough for my tires so they're underinflated reducing their effective radius?

 

[Skulking]

Thanks! My wife and I both installed the Speedometer app on our iphones and took the 4runner onto the freeway. The results were really strange though because both phones showed 3 mph faster than the 4runner's speedo at all speeds ranging from 40-80 mph. I thought I would be further off with 285/75R/16 tires and that the difference would increase as the speed increased. Perhaps 35 psi is not enough for my tires so they're underinflated reducing their effective radius?

The difference should increase as the speed increases. Your actual speed should be ~7% higher than what your speedometer reads based on the tire size assuming your speedometer is calibrated for a 265/70/R16. If your speedometer was calibrated for 225/75/R15, then your actual speed would be ~16% higher than what your speedometer reads.

 

[Romeo1]

My SX 99’ has 4.30 axles and the speedo is dead on with 265/75. It says 15” wheels on the doors.

 

[Option01]

The difference should increase as the speed increases. Your actual speed should be ~7% higher than what your speedometer reads based on the tire size assuming your speedometer is calibrated for a 265/70/R16. If your speedometer was calibrated for 225/75/R15, then your actual speed would be ~16% higher than what your speedometer reads.

Yeah, that's what I expected too and was surprised that the GPS reading was off from the speedo by the same amount regardless of speed.

My only guess is that 35 psi is not enough for the new tires to be fully inflated so they are currently very close to the stock size and that the 3mph difference is just a fixed variance between GPS and speedo.

The freeway I tested it on does have some curves and hills so maybe I'll give it another test next time I'm on a straight and flat section.

 

[Skulking]

Yeah, that's what I expected too and was surprised that the GPS reading was off from the speedo by the same amount regardless of speed.

My only guess is that 35 psi is not enough for the new tires to be fully inflated so they are currently very close to the stock size and that the 3mph difference is just a fixed variance between GPS and speedo.

The freeway I tested it on does have some curves and hills so maybe I'll give it another test next time I'm on a straight and flat section.

It's impossible to know if 35psi is too low for your tires without knowing what you are running, and how much extra weight you may be carrying, and even then there's some personal preference involved in that. I know that for me 35psi would actually be higher than I'd want to run.

Either way, I don't believe you actually have a fixed difference between the speedometer and GPS, you likely just can't read the speedometer accurately enough to see the change. If you did have a fixed difference, it wouldn't be due to tire pressure because the tire pressure impacts the diameter which means whatever affect it has will be tied to speed just like changing the actual tire size.

 

[Endlessblockades]

It's impossible to know if 35psi is too low for your tires without knowing what you are running, and how much extra weight you may be carrying, and even then there's some personal preference involved in that. I know that for me 35psi would actually be higher than I'd want to run.

Either way, I don't believe you actually have a fixed difference between the speedometer and GPS, you likely just can't read the speedometer accurately enough to see the change. If you did have a fixed difference, it wouldn't be due to tire pressure because the tire pressure impacts the diameter which means whatever affect it has will be tied to speed just like changing the actual tire size.

I run 45psi on 265/75/16 mud terrains and have no problem climbing mountain highways or driving for hours at Interstate speeds with 4.30 gears. As soon as I hit dirt I'm at 18-20psi. I popped out of the desert on my last trip to get supplies and forgot to air up and drove 40 miles at 70mph at 20psi - I realized my mistake as soon as I absorbed a speed bump in the liquor store lot and immediately checked my sidewalls - not hot at all, so no harm done! But anyway - I have a dumb question: where does my Ultra Gauge pull the MPH data from? The ECU, I suppose, but what is the equation/sources? It's always a couple mph off the the dash "gauge". Slower, if memory serves.....

Edit - I added the Trans Temp reading to the gauge but I do not recall doing any odometer/mph calibrating.

 

[Bad Luck]

Yeah, that's what I expected too and was surprised that the GPS reading was off from the speedo by the same amount regardless of speed.

My only guess is that 35 psi is not enough for the new tires to be fully inflated so they are currently very close to the stock size and that the 3mph difference is just a fixed variance between GPS and speedo.

The freeway I tested it on does have some curves and hills so maybe I'll give it another test next time I'm on a straight and flat section.

I would think it's more likely that the stepper motor for the speedometer or the needle attached to the speedometer stepper motor is off by a degree or three causing your fixed speed variation.