Hello!
My 2009 Rx is due for a tire change.
I personally want to put on bigger tires. Plus! My speedometer is fast. When it shows 63mph, my GPS says its 60mph.
Im thinking the quickest way to remedy this is bigger tires.
Im thinking 236/65r18. On stock wheels.
I read it might not fit due to the perch on the rear shocks but I already changed mine to highlander shocks so the perches are higher.
What are your thoughts on this? Is there anything else I need to consider?

Thank you for sharing your thoughts!!

 

Most vehicles read about 3mph faster than they're actually traveling so people drive slower. I have slightly bigger than OEM (3% bigger) on my 06 RX330 and so far it's made little difference. Physics says that bigger tires will require more energy to get rolling but maintain speed better, so worse mileage around the city but potentially better highway mileage (although bigger tires will raise the vehicle farther off the ground, which increases drag).

It will also make your odometer read fewer miles than you're actually traveling, increasing your resale value!

 

what size did you get?

did you have any problems with fitment?

Thanks!!

 

You're joking, of course. Standard tire size would be 235.

Just get used to your speedo.

 

Running 235/60R18, OEM for me is 235/55R18. It's about 1 inch bigger diameter. I'm about 2/10ths of an inch away from being too big for the stock struts, so it works totally well but it's just about as big as you could run.

I'd probably just run normal OEM size if buying full price, but I got a full set of really nice tires off FB marketplace for $200, practically brand new, and I figured they'd be close enough!

 

all speedos read slightly faster than true speed due to safety standards that state they cannot read slower than true speed.

 

If your want bigger tires & are running the oem wheels, best to go w/ 245/55's.....

 

If you want tires you're in good hands with @Felix .
He's a guru on this stuff. 📣 😀

 

I want to also switch my struts to Highlander struts to increase tire clearance from the springs' perch.

were you able to re-use the RX's stock links to the antisway bars? if not, what did you use?

 

thank you so much! Is 240/60 too big/heavy?

 

Yes, stock everything else. Its a tighter fit because its going to be a longer strut but we made it work.

 

If you mean a 245/60x18, its a 29.6'' diameter tire, while a 255/55 is a 29'' diameter works better. IDK what kind of performance your looking for. I found the oem 255/55 works great on a 8.5'' width wheel. You'll find the vehicle more responsive, cornering, braking, ect. It squares up the tire thread. You'll find a 8.5''x18 w/ a 10mm offset fits flush w/ the fenders which adds the track width.

 

Wow thank you so much for sharing these specs!

Honestly i just think the stock tire diameter is too small for the RX and installing bigger tires might make it look better. Also, im thinking of putting A/T tires on mine.

 

If your wanting to close the gap between the top of the tire & fender, Why not lower it? As you know the 1&2 gen rx's are have more wheel/fender gap. If your wanting a little more handling performance, Why not add a 1.5'' of track width, which will also make your fenders flush w/ the tire/wheel assemblies. The oem 235/55's will fit 8.5'' width wheels which will square the 235/55 tire shoulders which will improve cornering vs the taller squishy 60 seried tires on your oem 7'' width wheels. If you like the vehicle & it serves its purpose, Why not hitup a Discount tire & order a set of 8.5x18 wheels w/ zero offset & either use the tires you have or a new set of 235/55-18 tires. For more braking performance, add the gen3 front brake setup, pads/rotors & a pr of reman calipers, which is direct bolt on. One look at the 2nd gen #1005 pads vs the 3rd gen #1324 pads as well as single piston calipers vs twin piston calipers. & since your there add new brake hoses or better yet SS hoses. Throw your oem calipers in the boxes & get your core $ back. A new set of KYB struts using the oem springs will help also. More cornering response, add a 19mm Ultra racing rear anti-sway bar. This will give you a great entry level, cost effective handling machine. If you want the next step, add a set of 9.5''-10'' zero off set wheels, 29545/18 tires, a 2nd gen 908-13)highlander rear pads, rotors & a pr of reman calipers & the Corolla GR front brake up grade, 4 piston calipers/ 14'' rotors or a aftermarket BBK which there are several manufactures & choices, 330mm,345mm, 355mm + # of caliper pistons. More exhaust flow/less resriction, 2.5'' exhaust, Walker quiet flow SS muffler using the oem rear resenator which is still oem quiet.

 

Wow, so that is how you would build an rx f sport.
But I do have the 3rd gen rx bkk on my cart in rockauto. I have not pulled the tigger yet.

But my tires are due, hence this thread.