Link to home
Start Free TrialLog in
Avatar of sunhux
sunhux

asked on

15 or 16" rim for Toyota Sienta : pros & cons

Car dealer told me 15" saves more fuel & is more suited for Sienta hybrid  (& Airwave)
while 16" is more suited for Toyota C-HR.

I like 16" so that my bumper is not too low & often get scratched when reverse-parking
or head-in near high pavements (have seen pavements of 9-10" higher than parking
ground)

Q1:
Is this true that 15" saves more fuel?

Q2:
which one can accelerate faster or no diff?

Q3:
which one is more stable ?  I tend to think lower centre of gravity makes
an object less likely to overturn
Avatar of David Johnson, CD
David Johnson, CD
Flag of Canada image

A1: There is the rim size and the aspect ratio of the tire.A tire with the same aspect ratio but a larger rim size will require less revolutions to reach the same road speed.
A2: Acceleration is more dependant upon torque (horsepower) Again larger tires require less rpm to achieve a faster speed. It also depends upon the friction coefficient of the tire itself (fatter tires have a larger contact area and depending upon the tread pattern (or lack thereof) have a higher friction coefficient before they slip when accelerating you want to be at the edge of the tire slipping (burning) to achieve maximum traction.

A3: Yes the lower the center of gravity the less likely to overturn.

One also has to consider the sprung weight vs the unsprung weight (the weight above and below the springs)

There also is the design of the wheel wells.. is the car designed to have 16" wheels with tires of the same aspect ratio of the 15" rims?-
SOLUTION
Avatar of serialband
serialband
Flag of Ukraine image

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
ASKER CERTIFIED SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Avatar of sunhux
sunhux

ASKER

I m quite newbie in this.  Oddly the site gave Sienna   instead of Sienta.  The closest I got is   https://tiresize.com/tires/Toyota/Sienna/2000/

Its sienta 1.5 G (A)   2017 make according to my dealer.  Does above link mean its meant for 15" rim?
SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Avatar of sunhux

ASKER

Attached is what I've seen from the site: looks like every possible models of 2017 Sienna indicates 15" rim:
so going by the last post above from Ramin, does it mean there's a leeway of upgrading the rims by 2" ?
ToyotaSienna_Rimsize.JPG
SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Avatar of sunhux

ASKER

One more query:

So if I stick with 15" rim, I can still go with 16" tyres?


I narrow down to 3 options below & is considering option 3 if it's as comfortable as Option 1 & yet gives best performance?

Option 1:
Rim Diameter = 15 inch  = 381 mm
 Total Tire Diameter with Rim = 185 * (60/100) * 2 + 381 =  603 mm          // Acceptable Tire Diameter  
  // Good Comfort,   Good Performance,  The most accelerate because of more Tire's diameter //

Option 2:
 Rim Diameter = 16 inch  = 406.4 mm
 Total Tire Diameter with Rim = 195 * (50/100) * 2 + 406.4 =  601.4 mm     // Acceptable Tire Diameter
  // Comfort is NOT acceptable,  Very Good Performance//

Option 3:
Rim Diameter = 15 inch  = 381 mm
Total Tire Diameter with Rim = 195 * (50/100) * 2 + 381 =  576 mm
// ??,  ?? //
SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
If you go to a non-standard wheel rim and tyre configuration such as you are suggesting you will find that when you come to replace the tyres they will be expensive.  Because they are not a normal off-the-shelf tyre they will cost more.
SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Well there you have it. I hope the OP hasn't gone and bought 16" rims already.

It's too bad Edd China isn't on Wheeler Dealers anymore. I learned a lot from him over the years.
Avatar of sunhux

ASKER

So from the LTA link  / extract,

a) The size of the sports rims should be in accordance with the car manufacturer's recommendations.
Both 15 & 16" rims are within Sienta manufacturer's recommendations, aren't they ie as per link below?
https://www.wheel-size.com/size/toyota/sienta/2017/
Extracted from above link the 2 lines below:
  5.5Jx15 ET39  <== 15" rim
  6Jx16 ET45     <== 16" rim

c) The overall rolling radius of the original wheels and tyres should not be altered.
The radius will get changed if I increase to 16"
SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
SOLUTION
Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Thanks for fixing my math, dbrunton. I forgot to double the width of the tire in my calculation.

Note, however, the manufacturer-recommended tire for 16" rims is 195/50R16 instead of 195/55R16. That would result in a 601.4mm outside diameter for the tire. It's almost identical to the 603mm 185/60R15 tire for the 15" rim and might receive LTA approval. (Your odometer would be off by 266 KM when it shows you've traveled 100,000 KM.) I would still check with LTA before buying the 16" rims, since they're not manufacturer-recommended for the Sienta Standard.
Thanks,
I'm glad we could help.
Thank you sunhux