alfaromeo3

iTrader: (4)

Please post pics of ur NX followed by wheel specs!



Lexus NX 200t rides on 21-inch HRE P104 forged monoblock wheels in gloss black with Toyo Proxes T1R Sport tires size 265/35-21.

Im debating if I wanna put 20" or 22". But 360 Elites NX with 21" looks ideal!
Im going to Velgen this week to do some test fitting for the right size & right offset.

corradoMR2

Good thread.

WHEELS
Braelin BR-02 (in the US, Ace Convex), custom painted "Midnight Graphite"
114.3 x 5
20x8.5"
+35mm offset
hubcentric bored to 60.1mm
27.6 lbs
$1150 (set of four)

TIRES
255/45/20 105XL Yokohama Parada Spec X
32.0 Lbs
$900 (set of four)

PERFORMANCE
No rubbing
As smooth, comfortable, and quiet as the OEM Michelin Primacy MXM4 225/60/18s
Improved cornering dry grip
Good snow traction
Fractionally slower takeoff
1-2 MPG drop

emoowear

Thanks for the inspiration corradoMR2.






Rims/Wheels
Five Axis R5:f , Silver
19x8.5
5x114.3
et30
$860/set

Tires
Firestone Firehawk Wide Oval AS
245/50/19
$650/set

So far so good; Just got them put on so we will see but rides just as comfortable.

emoowear

Figured I'll post my question in here:

What's the recommended psi you guys are running your tires on?

I know the door jam has info on psi but is that not for the oem/stock size tires? Been trying to find info on the interwebs but there are a lot of split findings/line of thought on this.

I'm running 245/50/19 now which are a little bigger than stock/oem. The new tires says max psi@51, so I'm thinking of running it at 46? is that sensible or is that still too high?

There's also the comfort V mpg saved argument; lower psi =softer ride at the cost of mpgs. I'm ok with the harder ride w a higher psi.

Can anyone clarify?

corradoMR2

46 psi is too high and can be dangerous as you are at a higher risk of a tire blowout during prolonged use in hot weather.
I personally wouldn't go more than 40 based on your preferences.

I have my 20s running at 32 psi as I want the comfortable ride at the slight expense of handling and mpgs.

rVague

When I got my car the tires were overinflated to 39 psi and driving it home it followed the curve of the road and didn't track straight. Next day reduced to 35 psi ( per the door jam) and feels much more comfortable.

emoowear

Thanks for the input guys.

In the mornings, the gauge reads at 36 for front and 35 for the rears. After driving for a bit, they plateau at 39 for the fronts and 37 for the rears. Is that normal or still too high? I didn't add anymore air by the way. Those were just the numbers when I got my new set of wheels.

I am only asking because I noticed in one of the photos i took recently, the front wheel looked a little flexed and under-flated. Is this normal due to me turning the wheel?

Stitch626

iTrader: (2)

Absolutely loving the gloss graphite CVT's





This makes me miss my VFS2 in gloss graphite!

emoowear

Diggin' that Blue/black combo

Swacer

What is on the door is for the OEM tires. However, most tires are all around the same range, regardless tire/wheel combination. 46 is WAY too high.

Something to keep in mind, a gas fills a volume in which the pressure at all points is the same. Thus, even if the tire and wheel size is different, the same pressure applies. Why? Because that is the pressure that is pushing against all parts of you tire. For a normal street tire, 32-35psi is pretty normal. You should continue with that.

Also, the comfort vs. MPG does not apply for how you wish to apply it. You run a lower psi for grip, long with the cushioning of some contact with the road. What that says is that by running the OPTIMUM tire pressure, you are able to reduce your contact patch and remove rolling resistance. Less kinetic friction, less work done by your engine. What you've done by going to 46psi, is blown that way out of proportion. What you've done is now created a situation in which your tires are severely wearing on the center of the contact pad (your tires are now less of a square with its top missing, but now more like a U in which the sides to not touch). The MPG you "think" you're saving, will mean nothing when you're chewing up the center of tires every 10k miles.

Finally, your tires are going to give you a max pressure. They are usually in the low 50s. That is the maximum HOT tire temperature under the load of your car. If you're 46psi cold, assuming ideal gas laws, hot, you will be 50-51 psi, and now you are risking blowing a tire. Again, is that 1mpg worth wrecking your car?

I'd say its about 1-2psi high, but I don't know the ambient conditions when you looked at the pressure. Was it 50 degrees out? 90? In direct sunlight? In the shade? A lot of factors at play. Throwing out a number does not tell much of a story.

A front tire will always look underinflated...its holding the weight of the engine.

emoowear

Swacer, Thank you for the detailed run down. I will reduce the psi by a few per your suggestion. This is my first set of after market wheels ever and was worried about the flexing of the tires. Thanks!
Is it normal to have the back set at a lower psi than the front? Is it due to the engine being in the front?

Swacer

not a problem. However, one thing, you didn't say what the conditions were when you checked the tire pressure. That will change my response to you. What was the temp? Were the tires in the sun or shade? Then I can give you a better idea.

No, you want all the tires at the same pressure. The only exception to this would be if you're running different diameter front and rear wheels. Then its a different story. But if all the wheels are the same size, I would put all of them at 34-35 psi when cold and ambient air is 70 degrees and see how it drives. Adjust accordingly.

The reason it looks "flatter" in the front is the weight of the engine as I said, and the lower the profile of the tire, the more that tends to show. You're still fine though.

emoowear

Ah gotcha. roughly 75-80degrees and under shade when I initially checked them. From that point on, I used the sensor readings from inside the vehicle.

Ah okay, I've got some adjusting to do then. I think I will need to invest in a legitimate air pressure gauge.

Swacer

If it was 75, then just make the tires 34 psi all around. See how the car drives and see tire wear. You'll find the pressure that works ideal with those wheels in time.

I actually just bought wheels for my camaro, and I'm going to be doing the trial and error myself with my first set of tires.

emoowear

Swacer,

K got it. Will try that! Thanks a bunch. Man, good luck on the camaro...always thought they looked sweet w their aggressive front.