[GetzUThere]

Hi all,

i recently upsized my 13" 175/70R13 stocks with 14" alloys and 185/60R14 tubless Goodyear Ducaro. Arguably since my profile has been reduced by 11.5 mm the ride quality is suffering considerably... Have reduced the tyre pressure from 30psi to 28psi on all 4 tyres. Still the ride is pretty much harsh even when there are 5 passengers...
What would be the ideal pressure so as to reduce the harshness... Is a change of size to 185/65 required or must i reduce the trye pressure still further. How will this affect my millage..

Regards
GetzUThere.

[speedsatya]

Originally Posted by GetzUThere

Hi all,

... Have reduced the tyre pressure from 30psi to 28psi on all 4 tyres. Still the ride is pretty much harsh even when there are 5 passengers...
Regards
GetzUThere.

you have got the right upsize ...but never reduce the tire pressure ...infact as u go lower down the profile ...an increase of 1-2 psi is recommended...underinflation is one of the main reasons of tires bursting at high speeds...

and ur side wall is 185X0.6=111mm instead of 175x.7=122.5mm...so thats the reason for that harsh ride .....but dont reduce the tire pressure

[GetzUThere]

Originally Posted by speedsatya

you have got the right upsize ...but never reduce the tire pressure ...infact as u go lower down the profile ...an increase of 1-2 psi is recommended...underinflation is one of the main reasons of tires bursting at high speeds...

and ur side wall is 185X0.6=111mm instead of 175x.7=122.5mm...so thats the reason for that harsh ride .....but dont reduce the tire pressure

Thanks for the inputs. But raising the tyre pressure would make the ride harsher. Most of my driving is gonna be city driving that too Mumbai .... Bumper to Bumper... with the lovely poth-holes to accompany me

[viper]

Hey,

Tyre pressure will not solve your problem. It is your tyre which is the culprit. The Ducaro is a hard compound tyre hence your problem.

Viper

[GetzUThere]

Originally Posted by viper

Hey,

Tyre pressure will not solve your problem. It is your tyre which is the culprit. The Ducaro is a hard compound tyre hence your problem.

Viper

Hey Viper...

if ducaro is hard, then which goodyear tyre would be better... i believe F1 would be even harder and also unidirectional which i dont require since i have almost nil highway driving...

thanks

[sAP]

Your sidewall is still a pretty good 4.4"; IMO not that *bad* enough to cause *such* a hard ride. Sorry I am clueless.... maybe its the tires afterall (*I am guessing here*).

Why don't u look up the tire bible here http://www.carbibles.com/tyre_bible.html and see if anything lights up.

sAP

[.anshuman]

go for the pressure suggested in the owners manual.

[kpzen]

Originally Posted by .anshuman

go for the pressure suggested in the owners manual.

After having done a tyre upsize you cant follow the manual which is applicable only for the stock wheel dimensions...

KP

[.anshuman]

Originally Posted by kpzen

After having done a tyre upsize you cant follow the manual which is applicable only for the stock wheel dimensions...

KP

but tyre size has nothing to do with tyre pressure.

[kpzen]

Originally Posted by .anshuman

but tyre size has nothing to do with tyre pressure.

When we upsize the tyre the sidewalls decrease to keep the same the OD.... Hence the flexing area of the rubber also decreases..
Earlier i had 145/80-12 in my zen and kept the pressure level 24-26 psi as recommended in the manual...Then i got upsized tyre to 165/65-13 and now i'm maintaining a min of 28psi and 30psi for highways..

KP