dougies549

LO troopes

Can u answer a question for me.

I am running sti 5 alloys with 205-50-16s and thats what tyres i was going to get,till i ws told that 45 were cheaper,

Now i am told the 45 would totally cahnge the gearing of the scoob is this true??

my 97 catalunya.

Ta Dougie+Diana

john banks

would reduce rolling radius and therefore lower "gearing" reducing top speed and making speedo overread more.

Beastie

iTrader: (2)

Thats why you would need to get 215 45 16s so that the rolling circumference is maintained.
Beastie

john banks

will they go on OEM wheels?

dougies549

Lo John

If i go for the 45, that would increase the speedo ?

Beastie

Surely if they come standard with 205 50 16 that's what should go back?

Or would i be better getting 17's and fitting 215 45s.

Ta Dougie+Diana

Dul

I was running Pirelli Pzero and Goodyear F1 in 205/45/16 on the standard rims. The difference with 205/50/16 is about 3,4%. Actually, I’m not sure but I guess when your speedo says 100mph actually it will be about 3.4 mph too optimist. Anyway, the gearing difference is almost not noticeable.
The ride is definitely sharper as the standard set up and you get a better feeling of the road.
As I got some very stiff suspension, I’ve found on typical bumpy roads in mountainous areas that the tires did not work enough (too stiff and not enough distortion to find the best grip)…. However I think it’s all about compromising….

Hope this helps!

Al.

john banks

I'm quite keen on trying 215/45R16 Toyos on OEM wheels as I'm a cheapskate. Presumably since 205-215 is a 5% increase and 50 to 45 is a 10% decrease, there would still be a reduction in rolling radius which would not be corrected until you go to 225/45R16 which would probably rub?

Or am I getting it wrong? Although if the 5% decrease in sidewall of tyre is taken into account with the whole wheel the difference in rolling radius would be around 1% - ie. inconsequential?

dougies549

Hi all

Now my head is spinning!!!!

What to do??

Dougie+Diana

john banks

I think what we are saying is that 215/45R16 would be better than 205/45R16 as the gearing is nearer to standard.

Dave T-S

Dougie

Right - put your head's handbrake on:

Rolling diameters:

205/50x16 = 612mm
205/45x16 = 590mm
215/45x16 = 600mm
215/40x17 = 605mm

These are from a Yokohama chart, and all the mfrs measure up slightly differently.

205/45x16 is too far out.
215/45x16 is just about ok.
215/40x17 is the closest.

[This message has been edited by Dave T-S (edited 15 August 2001).]

Dul

Well, 612mm and 590mm, the difference is about 3.6%. (pretty close to 3.4%)

Anyway, I will personally not put 215/45/16 on the standard rim. They may fit on the wheel but in my opinion the rim is too narrow. When driving very hard, the tires will have to support more deformations and would overheat quickly. If you run 205/45/16 you will not have any similar problem. You might just be aware of the tinny difference of the gearing…
I also guess many members of this bbs use 215/40/17 without any problem…
The rest is your choice…

Dul.

Beastie

iTrader: (2)

I use 215 40 17s instead of the original fitment 205 45 17s. (Car is RB5)
I can see no problem in fitting 215 45 16s to your standard rim.

However, I do not think you will be happy unless you feel you have fitted the correct tyres, therefore you should go for the original fitment or upgrade to 17 inch wheels. This is well worth it in my opinion. However, you will then find that 205 45 17s are expensive compared to 215 40 17s and you are back where you started.

At the end of the day its your decision.
Good Luck.
Beastie