will changing tyres to 215/55/17 create any problems?

IMHO oversized tires are not a good ground clearance solution. I would look at lift kits that raise the suspension knowing you may have limited resources. The reason is wheel well clearance, the rear is the critical part.

My experiments revealed interference on bumps actually rubbing tire against body. I moved those tires to the front where there is more clearance.

I recommend researching lift sites and vendors first BUT your time and money.

I am running oversized tired based on revs/mile to correct the speedometer and MPG metrics. I also did one pair at a time and moved them rear to front after testing on local speed bumps at different speeds.

Good luck!
Bob Wilson

 

How badly scratched? If I look at ours I'll see cosmetic scrapes, mostly from running over parking lot front wheel stops that were a bit too high. The front end in particular.

The first point of contact is often plastic underpanel, and mild abrasion I'm ok with. For me, it's only a concern if it gets to the point the underpanel fasteners are getting chewed up, are in need of replacement, and the panels are in danger of dragging.

 

I have found no computer option to change.

You might look at some towing suspension options. Some of them include spacers to increase the spring height.

How old is the car? If it has been heavy duty taxi service, it might make sense to have a mechanic check the springs in the front and back. The standard service ones might be sagging.

Bob Wilson

 

@nirmal I despise speed bumps; they are a penalty imposed on everyone, due to irresponsible speeders. They cause many, many problems.

 

@nirmal I despise speed bumps; they are a penalty imposed on everyone, due to irresponsible speeders. They cause many, many problems.

 

Have you tried taking the speed bumps at a 45 degree angle? Go slow also. How big are these speed bumps? They sound huge to actually get a passenger car hung up on. Lol!

And as stated above depending on age and wear and tear your vehicle might need new shocks / Springs..

 

I find diagonal speed bumps even worse, at least for the physical jostling. You get 4 jolts instead of 2.

 

There's mention in this Toyota document of "rough road package". Made me think of your problem, might be of help, something you could ask about:

https://techinfo.toyota.com/t3Portal/document/rm/RM1290U/xhtml/RM000001Y3B015X.html?sisuffix=ff&locale=en&siid=1471310109452

 

I am also from sri lanka. I have 2014 prius GS with GS alloys with 215/40/18 tyres. I have the same problem