OK Brother. First let me share with you the tire specifications of my Toyota Passo X, Model year 2013:
(This sticker will be placed when you open the driver door, and look towards the bottom of B-Pillar of your car)
My car came with 155/80R13, i.e. 155mm is the stock width, 80 is the aspect ratio and 13 is the rim size in inches.
When I changed the tires, since 155mm width tires were not available and the nearest available were 165mm, so i installed them. The tire specs. were 165/70/R13 and this spec. was the nearest to stock specs., and available at only one shop in the whole market by that time.
Let me share the pic. of invoice:
Brother you are using 175/70/R13, they are only wider by 10mm then my current tires, otherwise, aspect ratio and rim size is the same.
Brother did you check the sticker? I really doubt 175/65/R14 as the stock recommendation for Toyota Passo.
If this has been written on the sticker, kindly share the pic.
Brother if you change to 185/70/R13, tires will become wider and section height will increase a bit and overall, little to no effect!
If you change the rim size to 14 (which I really doubt is the stock one), you will be severely compromising over its suspension!
Solution:
Look at the sticker of your vehicle, which shows complete tire specs.
For optimum performance and best fuel efficiency, stick to the stock tires recommendations or nearest to it! If your specs are 155/80R13, try to get max. up to 165mm (Even 165 is wider to 155 by 10mm, so overall, 40mm increase in width on all the 04 sides. More rolling friction, more losses and more fuel consumption.
Now just imagine the effects, if width increases to 175, or even 185mm?)
I think 13" will be the stock recommendation. Please confirm and if this is the case, stick to 13" tire and rim size.
When you increase the tire width in comparison to OEM recommendations, you are increasing friction and losses, and decreasing fuel efficiency!
(Road grip may increase a bit, but at the expense of fuel consumption).
One should always stick to OEM recommendations, because a vehicle is designed and tested to work on it, and for best results!
(Agar road grip hi k baat ho jye, jaisa k hum kehtay hain k 155 p gari stable nai ho gee. If this has to be the case, then Japanese ney tires ki 155mm width kyun rakhi hai? Unhoon ney 165, ya 175... ya... 185 kyun nai rakhi?
Aesa nai hai. Hum apni taraf sey alterations kar k, ya kehnay sun'nay p; performance, fuel consumption, suspension... algarz, harr cheez ka kabara kar daitay hain!)
I would suggest you to revert to OEM specs. for tires ASAP and if your vehicle hits speed breakers, the only option would be to install additional small springs, with all the 04 tires. They will lift the vehicle reasonably and it won't hit speed breakers.
Japanese cars jitni b aa rai hain, subki ground clearance bohat kamm hai. Almost all hit speed breakers. Ye acha hall to nai hai (since it destroys car suspension in the long run), but at the same time, it is the only solution!
I have tried to cover everything in detail and with logic / knowledge. I hope, it all helps. If I made some mistake, please correct me and if everything is correct 
then, in case of any further query, please feel free to contact.
Thank you.
