Tyre Choice - 195/55 or 195/50

[Simon86]

I know the obvious difference, but is there something i'm missing when it comes to selecting one or other of the above sizes?

The car is an AE86 and will be used for trackdays and hillclimbs.

The rims are 15x8.5

Cheers

[Dell'Orto]

One of the tyre guys will pipe up, but AFAIK the main difference is the rolling diameter, which will throw out your speedo reading

[Simon86]

Yes - aware of this also - 50 series is near on the same as stock and 55 series is 3% bigger.

[strx7]

if the rims are 8.5 inches wide, I would have thought you'd be looking at around 215 or 225 width tyres? or are you going for that GHEY stretched tyres look?

[Simon86]

if the rims are 8.5 inches wide, I would have thought you'd be looking at around 215 or 225 width tyres? or are you going for that GHEY stretched tyres look?

195's on a 8in rim were the size previously run and in my opinion the best size for a NA AE86. Would consider 205's but have concerns about fitting them under lipped guards. 225's would look like balloons.

[strx7]

i currently have 225's on 7 inch wide rims on my 4wd 100 series club car., they'd be better on 7.5's or 8's

If you are worried about them fitting under the guards run a narrower rim.........

[Rick]

If you are going to be running those size rims on the road for a cert the minimum width tyres are 225mm wide.

[Simon86]

If you are going to be running those size rims on the road for a cert the minimum width tyres are 225mm wide

Really? Where did you get that information from? That makes me slightly nervous as there's no way I'll fit a 225.

[RomanV]

http://www.oldschool.co.nz/phpbb/viewto ... 67&start=0

[Simon86]

That's unfortunate.

[nz_climber]

Also I would be reading (and taking note) what the tyre manufacture says

For the sizes given above bridgestone states 5.5inch - 7inch Permitted (for a RE11) So going an extra 1.5inchs on top of that won't be great idea.

[rollaholic]

remember the above link is a rule of thumb and is applied at the certifiers discretion, so as long as it looks reasonably respectable i dont think you'll have a problem

tasteful stretch ftw

dont let all the old fogeys on TS put you off

[TRD Man]

It's not a matter of being "old fogey's". It's about what's practical or correct.
The LVV chart posted looks pretty good to me and I certainly wouldn't be stretching a 195 tyre onto an 8.5" rim.

On our FWD Corolla we ran 205/50's and 205/55's on 7" rims which are about right.

In terms of the rolling circumference, don't underestimate the effect of this. A lot will depend on your gearing.
I would think if you are running std drivetrain 50's would be the go.

[Malcolm]

it's funny how stuff like this is. I can't afford/don't want to spend the money on buying wide wheels for my car (if anyone ever sees any 4x100 8" wide rims on trademe, let me know ), so I've always tried to squeeze the widest tyres I could onto my 7" rims, but then you have people who get big fat rims and want to fit the skinniest tyres possible onto them.

Also the thread on old school is pretty crack up, using an F1 as an example to show stretched tyres are safe

[Mr Revhead]

Careful, you'll get abused

[FLAWLES]

Careful, you'll get abused

lol

nah cant be $&#$%

your safe haha

but yea each to there own i spose

[Malcolm]

Careful, you'll get abused

I'm always happy to enter into friendly technical debate on such matters

[tsoob]

go the 195 50, speedo etc. 205 50 would be ok as well

[rollaholic]

It's not a matter of being "old fogey's". It's about what's practical or correct.
The LVV chart posted looks pretty good to me and I certainly wouldn't be stretching a 195 tyre onto an 8.5" rim.

On our FWD Corolla we ran 205/50's and 205/55's on 7" rims which are about right.

In terms of the rolling circumference, don't underestimate the effect of this. A lot will depend on your gearing.
I would think if you are running std drivetrain 50's would be the go.

i dont think an 80s corolla is going to be at the pointy end of any field, unless the field is otherwise made up of 70s corollas. many, many cars have been running stretched tyres for many, many years. i have seen a few examples of it causing problems, but it seems to be only in extreme cases, both usage and stretch.

whatever benefits or penalites it may impose on your lap times are largely irrelevant imo, unless its a dedicated track car and you care about tenths of a second. if the owner likes it and has fun, whats the problem?

the old fogeys comment was largely tongue in cheek

[Simon86]

I have run 195/55's on 15x8 rims in the past with zero problems - the sidewall is virtually vertical, and was certified that way. Even prior to the new legislation there was still a cert requirement for the right section width tyre to be fitted to the rim, now it is clearly defined by way of a table.

However I think it is aimed more at people stretching 185's on a 9.5in rim or similar, but a line has to be drawn somewhere and the manufacturers 'recommendations' are probably a good place to start.