General Standard tyre size

[jimnewson]

hiya guys, i have a 1999 brava 80 sx, what is the standard tyre size that it comes with it. its just i'd like to know what the difference is in the speedo reading because i bought mine with 15' alloys and 195/45/r15 toyo tyres, and if possible can anyone advise me what size tyres i would need to get to get the speedo back to reading true? thanks for your time guys, james

 

[jimnewson]

sorry there should be a comma between 'to get to get'!!!!

 

[Hellcat]

195/50R15 are a pretty good match for normal Bravo/a sizes

 

[jimnewson]

thanks for the reply but thats not the size of the tyres that come as standard is it, its just i need to know the standard tyre size so i can calculate the difference, thankyou for your time.

 

[mountainmachine]

Standard with original alloys is 195/55/15

 

[Helz]

195/50R15 are a pretty good match for normal Bravo/a sizes

That's what I use and my speedo over-reads by exactly 3mph all the way up to 80ish so not bad.

 

[jimnewson]

thanks guys its just according to my sat nav (which i know isn't pin point accurate) when doing 70 im really doing 63ish and when doing 60 im really doing 54!!!!! its just irritating! is there anywhere i can get it tested? thanks to all though, take care.

 

[mountainmachine]

thanks guys its just according to my sat nav (which i know isn't pin point accurate) when doing 70 im really doing 63ish and when doing 60 im really doing 54!!!!! its just irritating! is there anywhere i can get it tested? thanks to all though, take care.

Thats becaus eyou have a 10% difference in the diameter of your wheel. So 1 revoloution is shorter than it should be.

Heres the calc for you:

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



So no point getting it tested as GPS is backing this up!

 

[mountainmachine]

Either that or contact your local police station, am sure they would be happy to do a speed test on you.

 

[jimnewson]

very funny!!!! but i think i'll choose the former!!!! thats sound just right though according to the diagram. thankyou very much, i dont suppose you could tell me what size tyres i would need to get it reading more accurate? thanks again.

 

[klemster]

standard tyres are 185/55 R15 according to the handbook

 

[mountainmachine]

very funny!!!! but i think i'll choose the former!!!! thats sound just right though according to the diagram. thankyou very much, i dont suppose you could tell me what size tyres i would need to get it reading more accurate? thanks again.

Depend on what your rims will take. Once you know the range you can play about with sizes and see the difference, you'll almost always have upto 3% diff which is acceptable.

 

[ZZR6]

185/60R14 I would think.
Mine is a 100 Trofeo with them on or 15's which i dont know what size

 

[zzip]

185/60R14 I would think.

mine standard was 175/60/14...

 

[Scorg]

When I got mines it came with original fiat fit steel wheels of 175/65/14.

Alloys on it now are fiat 185/60/14

 

[Hellcat]

Pretty sure they tend to use the same size wheels as Tipos.

175/65R14 or 185/60R14 on the steel wheels.

185/55R15 or 195/50R15 on alloys.

 

[jimnewson]

firstly: thankyou to all who have replied. secondly: after further research i have discovered that they are bk racing 166 alloys and they dont make this model in 15' so i went out and measured mine, turns out their 16 inch alloys running 195/45/r15, i always thought that the 'r15' was the diameter of the alloy or steel wheel meaning that it was 15' diameter, 195 was the width of the tyre and 45 was the depth????? so if i was right should my tyres be 195/45/r16???? sorry if this is confusing:bang:

 

[ZZR6]

Impossible. The rim is either 15 or 16" and the tyre will be the same diameter in inches.

If your tyre say 195/45R15 then your rims are 15".

The distance you probably measured was from lip to lip, not where the tyre bead sits

 

[jimnewson]

pk thanks mate for clearing that up!!! i did just measure from lip to lip, its just bk racing website says it doesnt do bk166 alloys in 15' only 14,16,17,18, so i measured it to 16' and figured they must be 16'!!!!!!!!!!!!!thanks again!!!

 

[ZZR6]