anyone been to performanceprobe.com? It shows you what your milage error will be depending on tire size, for instance 195's after 10K will read 9805 instead of 10K, also speed differential

 

I'm still running the OEM goodyears, 44,775 miles...I need to replace them real soon. As a couple of you may know (BoxO, bB) I'm into mileage big time' and so I've been running my tires at 37 psi all around for about 20,000 miles, and I must have missed a rotation or 2 because my front tires are just about completely bald on the inside (the side treds are much less worn), my rear tires are fine. I just rotated them and reduced my psi to around 34. I'll be replacing my tires the first week of may and I'm leaning towards the OEM goodyears, I've gotten great mileage using them and when it ices up around here I can pass other cars like nobodys business, one thing for sure I wont be running 37 psi anymore, it wears out the tires too fast and lets face it' good tires aint cheap!

 

Actually the speedo is calibrated for 185/65/15s. (bB OEM size) So 195/60/15 will be more accurate than the 185/60s.

 

try using this calcualtor.


http://www.1010tires.com/tiresizecalculator.asp

Now is it a 65 or 60 series for OEM? If you go with the 65 series ...

215/45R17 is only a click behind the stock size. I wold rather be under then over anyway.

 

Right, the speedo will be acurrate with 195s. But now the Odo will be 5% under what the milage actually is. 5th gear should feel slighlty taller too (there's a benefit)

 

^^The speedo and odo go hand in hand. Why would they be different? I'm not following your statement.

 

Exactly my same question a while back, Jeff, but a Mod locked the thread down it was being discussed in, saying the subject had already been beaten to death...unfortunately, even a search never really answered my question about it.
I still don't get the technical reason for it (and I'm really no mechanical idiot, I swear! ) , but it seems to be the accepted "truth", regardless.

 

Well if the speedo reads 60 for 1 minute the ODO should register 1 mile if they are in sync.
So if both are set for 185/65/15 and they come with 185/60/15 they should both be off by.... Here is what a tire calculator says.

When speedometer reads 60mph (96.6km/h) actual speed will be 58.3mph (93.9km/h): 2.8% slower.

So when running 195/60/15 it will make the speedo and ODO only off by 1%. That will work for me!

 

with out the speedo cable the odo doesnt work.

 

From what I understand, having read and posted in that beaten-to-death topic:
The odo and speedo are not connected. The ECU just tells the odometer what to display. It has no direct correlation with the analog speedo. From what I've read here. The tires are such that our speedo reads 3% too fast, and conversely the Odo is 3% light on miles traveled. That is why everyboby is saying multiply your miles on your tank by 1.03 to get a more acurate MPG calculation. There is about a 5-6% difference between what speedo says and what the Odo says, and USDM tires fit in between.
I have no proof of this, but I gathered this info from others on here, who say they got this from Toyota.

 

Even so, that would lead me to think that running a slightly taller profile tire should make one of the 2 more accurate anyways. Seems like 195/60/15 should have been the OEM xB sized tire all along.
It doesn't matter to me anyways cause I will never be buying the OEM size tire again.

 

Just picked up a set of '03 Si wheels (Civic) that is...Blasphemy! 15" Alloys and I'll be running Falken Ziex912 195/60/15's-65K warranty vs ASX's 30 or so for the same $. I'll post the picks soon as I get those tires mounted. Hey anyone know the weight approx. on our stockies? I know the alloys are lighter.

 

Got 2 agree with bb2ner, performance probe.com shows 10000 miles reading 9805 with 195's vs. 185's

 

The 29 psi recommended is a little low. I usually run 30-32 all around. It depends on how you want the ride. If you're doing long trips, lower pressure will give you a softer ride. Higher pressure will be a little rougher. If you're running 29 for normal use, expect the outside edge of the fronts to wear a little more.

 

I'm really surprised that Toyota suggested such a low pressure? That might be part of why the EPA mpg. averages were so low.

 

i am running them off the psi on the tire witch says 44 i know it says 29 on the door but i always keep it at 44 is this bad?

 

I think 44 is maximum, but 32-36 is probably better?

 

cool i will change it to 35 today thanks

 

I'm guessing it had to do with ride comfort. Running that low a psi effectively makes the tire sidewall part of the suspension, absorbing some of the harshness of the little Boxes' ride.
I can start to tell the difference in ride quality at about 33-34psi, and although it definitely helps mpg, it only gets worse from there.

 

44 PSI .. man that would be like riding on concrete wheels .. think Flintstones! Ouch