Hey there guys, question not bout my car, instead my gf's hyundai elantra. Recently was serviced and had all 4 tyres replaced and balanced etc. Now gf has asked me this wkend to check the tyres as they looked quite flat. Instead what i have found is that when the tyres were replaced, the incorrect ones were put on. Car is supposed to run 185's all round, but the mech put on 195's. Now what i want to know is this gonna cause any probs, ie increased/uneven wear? The sidewalls look far more "flexed" and make all tyres look permanently low/flatter than they should, even when the right psi is in them.

Basically wanting to know whether or not i should make the mechanic replace them? As he f'ked up :doubt:

You probably just need to run higher pressure than what's on the placard, but what is the actual size of the tyres, and what's the size of the rim?

16inch rim, which is meant to be running 185/65's and its got 195/65's on it now. I put the psi up to 35 from what it was meant to be (29/30 iirc), made no difference to the look/shape of the tyre.

16xwhat?

Ahhh pretty sure 5.5 inch wide, not 100% sure tho could be 6, cars not with me at the moment

Ok its a 15x5.5 rim

195/65R15s are fine for 5.5-7.0" wide rims.

Cool cheers mate, just wanted to check as it looks weird lol

Yeah, didn't Mitsu fit 215/60R16s to both 16x7 and 16x6 rims? As long as the steering doesn't feel totally wooly or front end response markedly affected, I wouldn't worry about it. Maybe 195/65R15s are cheaper.

now that wider tyres are on the speedo will be out
the speedo now reads lower then what speed your actually doing, i think its about 2.1k's out when the speedo says 100k's

now that wider tyres are on the speedo will be out
the speedo now reads lower then what speed your actually doing, i think its about 2.1k's out when the speedo says 100k's

How does the width of the rim effect the speedo, always thought that only happened if the diameter of the wheel/tyre combo changed :confused:

How does the width of the rim effect the speedo, always thought that only happened if the diameter of the wheel/tyre combo changed :confused:
it has a wider tyre does it not? could of sworn you said its got wider tyres
either way it has different sized tyres from stock but same rims which equals different rolling diameter which then equals a false reading speedo
http://www.miata.net/garage/tirecalc.html you have a play around with it ;)

How does the width of the rim effect the speedo, always thought that only happened if the diameter of the wheel/tyre combo changed :confused:Width of the rim does not. Width of the tyre does. The 65 in the profile refers to the side profile of the tyre in comparison to the nominal width (185 or 195). So the 185/65 tyre has a sidewall 120mm high, the 195/65 tyre a sidewall 126mm high.

Speedo wouldn't have been as accurate as a Magna's anyway. Grab a satnav to check it.

it has a wider tyre does it not? could of sworn you said its got wider tyres
either way it has different sized tyres from stock but same rims which equals different rolling diameter which then equals a false reading speedo
http://www.miata.net/garage/tirecalc.html you have a play around with it ;)

Huh didnt know that the width effected it in that way, thanks Rob. Seems that it will be a 2% drop in speed compared to what is indicated i think, if my poor maths skills are correct lol so not too bad i suppose

Width of the rim does not. Width of the tyre does. The 65 in the profile refers to the side profile of the tyre in comparison to the nominal width (185 or 195). So the 185/65 tyre has a sidewall 120mm high, the 195/65 tyre a sidewall 126mm high.

Speedo wouldn't have been as accurate as a Magna's anyway. Grab a satnav to check it.

Yeh meant tyre sorry, again this isnt on my car its on my gfs hyundai. Thanks tho guys

fyi, you'll (she'll) be going faster than what the speedo says.
Also, it's a 6mm increase in radius, so double that for diameter increase. I think that on paper it's actually 13mm.

in NSW, the diameter of the new wheel/tyre combination has to be within 15mm of factory tyre/wheel options on the tyre placard.
It might pay to check that 13mm is within the W.A. regulations.

Other than regs, you shouldn't have any problems with such a small change.

195/65R15s are fine for 5.5-7.0" wide rims.

When tyre manufacturers state wheel width as being OK that only means the tyre will fit without damage due to wall deflection/stresses. However it doesn't mean that that size will give good tyre wear or handling. Wider wheels typically give firmer/rougher ride but better steering response and lower wear while narrower is the opposite; more wear and poorer steering. The best rim width for 195/65 is 6 1/2". Thats what Mercedes use, but 6" is OK. With good quality grippy tyres a good rule of thumb is wheel width should be equal to tyre tread width when the tyre is half worn(tread width grows as tyre wears).


Yeah, didn't Mitsu fit 215/60R16s to both 16x7 and 16x6 rims? As long as the steering doesn't feel totally wooly or front end response markedly affected, I wouldn't worry about it. Maybe 195/65R15s are cheaper.

Yes Mitsubishi fitted 215/60 to both 6" and 7" wheels. With narrow tread poor grip tyres the 6" rims are just acceptable. If you measure 215/60 tyres you will see they vary in tread width from 6" up to nearly 7". My AWD had Bridgestone Turanzas on originally with 7" wheels. Horrible tyre with no grip and 6" tread. Then I fitted Bridgestone Grid III and handling was much improved. The Grid III has nearly 7" tread and better quality rubber.

Cheers,
Alan

putting 38-40psi in those tyres will also help greatly.

Thanks for the advice fellas, spoke to the mechanic today, hes gonna change them to the correct type free of charge :happy: