Bigger tyres on smaller rims

[possumboy]

The standard tyres on the Corolla Ascent are not that great. I have just bought a 2002 which has alloy wheels (a dealer special deal at the time, they look like Echo ones, 8 spokes grouped like a 4 spoke) but they are only 14's (5J). Ok, my AE82 TwinCam had the same size rims, so not the end of the world.

The tyres are 175/70 14. Would I be too nuts to put 195/60s on it? That would give me enough tyre to suit my driving needs (presume I get a quality sports tyre, have had Dunlop W10, Yokohama A509 in the past). The old AE82 had 175/65 on it standard and I put 185/60s on it. This would mean a different rolling diameter between the two cars on the same size rims. Don't know about this as that would be a problem for the speedo accuracy - I guess the models are different so the tyre/rim combo is not comparable.

Or I could go completely nuts and buy bigger rims, possibly from a higher spec 'rolla. There have been a couple of guys advertising Sportivo rims and tyres for sale which the have (presumably) replaced with big, sick azz wheels.

ideas? opinions? 2 cents worth?

[126]

you already have the largest size (width) tyre which is 175. on a 6" wheel you should not go more than 177.8

if you need 195 you need to start using at least 6" width wheel.

[possumboy]

Hmmmm. My old AE86 had 14 inch rims which were the same size (5 inch wide) and I had 185/60 tyres on that, worked fine and were fitted by pros.

Have noticed that the standard tyre on the newer cars is a 195/65 on a 15 inch. Wouldn't this give a different rolling diameter to my 175/70-14 set up?

Think I might call Toyota to see what the rolling diameter should be for the car. Don't want to pick up any speeding fines because of dumbass stuff like this.

[126]

you take the width of your wheel. add 2 inches. convert this to metric. this is the largest size you should have.

look in your glove box for a sticker. this is your tyre placard. if it is not a sticker in your glove box check your doors for a metal card or your fuel door.

the tyre placard tells you what wheels/tyres you have from factory.

[possumboy]

Thanks orrock.

I checked with Toyota and the 175/70-14 are the correct size for the car. Spoke to a couple of tyre guys who would happily put either 185/65 or 195/60 tyres on these 14inch rims. They say the rolling diameter is almost exact for most tyre brands so no speedo problems. Both also thought the idea of buying a second hand set of Sportivo 16in rims was a top plan. I'll just ask about when it comes time to do it. Just gotta sell some 14's nice a cheap!

[126]

please remember when you say 175/185/195 it has nothing to do with 14". 175/185/195 relates to width.

the general rule i know is wheel width plus 2. therefore for 5" width the maximum size should be 177.8 (5" + 2)

1" = 2.54

if you use 195 then the tyre will be fat over the wheel sides.

[possumboy]

Thanks

I know that you get a bit fat over the sides, but up to a certain point it is ok. 70 profile is a bit 'tall' and the original spec tyres a fairly crappy. A 185 with 65 profile (same diameter as 175/70) would be much better, but I was not sure if a 195/60 (next size again) would be safe to fit to the rim. Tyre guys say '+ two sizes' (not quite what you are saying - are there two different rules of thumb that we are each talking about?) is ok, but the third size up (205/55?) would pull off the rim :o . Being a little fat over the side of the rim is good also because if you rub the curb when parking you don't mess up the edge of the alloys B)

Think I will go the path of buying second hand Sportivo rims because they will bolt on, give me much better rubber (size and type) and they are Toyota items so the car will look OK and not give me insurance hassles etc. :D

[126]

Tyre guys say '+ two sizes' (not quite what you are saying - are there two different rules of thumb that we are each talking about?) is ok

i have already said the general rule i know is wheel width plus 2. there is just one rule.

[rolla02]

Guys,

You can use these tyre size calculator. Works a treat.

"http://www.miata.net/garage/tirecalc.html"

OR

"http://www.toyo.co.uk/index.php?fuseaction=tyreconverter.welcome&PHPSESSID=8e1b19608f21ebe4081070c8a4ca58cc"

Cheers

Tim.