I have the optional 20” wheels on my 2016 RX 450h. Ever since my car rolled out of the dealership delivery area, it performs horrible in the wind. What I mean by that, is the car is extremely affected by crosswinds & headwinds. When I changed from the factory Bridgestones to Pirelli, it seemed like it got worse, to the point that I despise driving it on a long trip if there will be wind in the forecast. If there is no wind, the car handles nicely for what it is.

I have looked for stiffer sway bars, springs & struts, but there just aren’t any parts like that, made for this model vehicle. It’s almost time for new tires & the manager at Discount Tire thought that the Pirellis might be the culprit. Perhaps he’s right, as the Pirelli Scorpions are much quieter & smoother than the Bridgestone Ecopias.

Thinking about tire shopping brings me to my question; would going to a lower profile & perhaps higher performance tire, help with the crazy buffeting & sway I get on a windy day? I only have 46,000 miles & could conceivably keep this car for another set of tires. I’m not here to debate tire brands, I just want to know if my theory is correct & is there a solution?

 

Ever had a wheel alignment done?

 

He said the car handles nicely with no wind. I have had Michelins and never noticed any problems in the wind.

 

It’s been aligned many, many times. If there was no wind, everything would be perfect. What’s strange, is the pickup I had, was all coil springs & it sat considerably higher than the Lexus, yet wind didn’t bother it, unlike the Lexus.

 

I don't have an answer but do have a couple of thoughts. The first one concerns tire pressure. I'm curious if higher tire pressures would reduce the sway. The RX's spec'ed 33 lbs is a little low compared to other vehicles of similar size with the same tires. Your truck like ran relatively high tire pressure, since trucks have high load ratings. It seems like higher tire pressures would simulate a stiffer sidewall. That could make a difference. Given the finicky nature of the wind, it would be hard to test scientifically, but still might be worth trying higher tire pressures to see if you notice a difference. Cheap to test, too.

The second thought is about your low profile tire question. It's well known in cycling circles that deeper wheels (think 'thicker' rim and shorter spokes for a given wheel size) do two things. First, they are more aerodynamic and thus much faster at a given power level. Second, they make riding in crosswinds really sketchy. I recently replaced the aluminum rims on my gravel bike with carbon ones that were just a little deeper, and I could definitely notice a difference in crosswinds. Lower profile tires on a car are similar in concept to more shallow wheels on a bike. A clear difference is that, unlike a bike, much of a car tire is 'covered' by the wheel well. Perhaps that means it wouldn't make a difference. Fluid dynamics is really complex science, though, so maybe it would help, after all.

 

I try to run 35 psi, but over time, they often drop to 32 or 33 psi, but I don’t let it go any lower.

I looked at Discount Tire online & there are no low profile tires available for my RX. I found that Toyota/Lexus likes to invent their own tire sizes. My Tundra had some crazy size that hardly any shop kept in stock. I’m assuming the RX is in a similar situation, as I could only select from 3 different brands of tires.

 

If you think low profile tires will solve your wind problem you can keep on dreaming. Not a chance in holy hell. Forget the tires, buy yourself a Corvette instead.

 

Think gadgetman1 has a Camaro SS if that counts.

 

I do & I’m restoring a 1970 Javelin - no need for a Corvette. Shockingly, my 6.2 V-8 Camaro SS gets better mpg than my Lexus…go figure.

 

It's a high, chunky vehicle, darn near square looking. The laws of physics wouldn't seem to be affected that much by just tires, but I'm certainly no expert. I see you're from Texas; if you're from the High Plains section, I know from experience you get some strong winds.

 

"Laws of physics" "what a concept" Thanks that there are some very intelligent people tuning in here. I appreciate that. Thank you SonOfABisc.

 

I have a 2015 Chevy SS Sedan that was manufactured at Holden Motors in Australia and imported to the states which didn't sell well here. It's packing a 6.2-liter LS3 engine that doesn't get better mpg than my RX.

My wife's 2020 RX 350 Non-F Sport has 20's Michelin tires running about 35-38 psi and gets pushed around on the hwy 70-80 mph and much worse if windy. It's not the most arrow dynamic design, and the ground clearance doesn't help. imo, wider and low-profile tires would make for a harsher ride with minimum stability improvement. Maybe replacing the shocks to a firmer one may help.

German cars / suv's are heavier with better suspension designed for speed and has lower ground clearance.
Drove my brother's x6 which handles much better on all accounts, but has a harsher ride compared to my RX.
His maintenance bill is also a little higher than mine annually.

 

Night & day differences between a RX & a X6. Have you seen the beefy tires BMW runs on those? They are often runflats, which only give a harsh ride. To my knowledge, there are no firmer struts available for the RX. It also sits way lower than most pickups & most of them don’t get pushed around like the Lexus.

Our Camaro does not have cylinder deactivation, because it’s a 6 speed manual. I can set the cruise on 75-80 & get 27 mpg all day long & sometimes 28 mpg. The RX stays between 23-25 mpg.

 

Yes, you're correct about those BMW oem tires. My brother swapped out the run-flats for something else I think Continentals.
My SS didn't come with the cylinder deactivation feature either thank God. GM has done a crappy job with their version.
I get about 23-25 mpg hwy running 93 octane with no tune done to my engine. My RX get 25-28 mpg on the hwy running 89 octane.

 

The Camaro came with Goodyear F1 runflats. They were very sticky in the warm, dry weather. They were noisy & rough riding & not hood in the rain. In the cold & snow, we had to park it. We put Continentals on it & they have been great. Unfortunately, they (Discount Tire) don’t offer those for the RX.