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A "simple" math/engineering question for 2014 IS350 F Sport, AWD.
Will the variance between front and rear in tire rotation from using 225/50/18 fronts and 255/45/18's rear (yes, I know these are large tires) damage the tranny, transaxle of mechanics if the car is used in snow/AWD mode? The original tires are a few rotations off on our cars, the rotations per mile is higher on this setup. Any real dangers or is there enough mechanical play between front and back to allow this setup?
Last edited by ShrinkDoc; Sep 7, 2018 at 04:01 PM.
A "simple" math/engineering question for 2014 IS350 F Sport, AWD.
Will the variance between front and rear in tire rotation from using 225/50/18 fronts and 255/45/18's rear (yes, I know these are large tires) damage the tranny, transaxle of mechanics if the car is used in snow/AWD mode? The original tires are a few rotations off on our cars, the rotations per mile is higher on this setup. Any real dangers or is there enough mechanical play between front and back to allow this setup?
The rotation may be higher, but the profile sizes are where you want to be careful. You’re still running correctly at 50 front 45 rear, the trouble starts when you try to run same profile front to rear or higher in the rear vs front, although most manufacturers engineer up to a 10-15% variance built in for such situations for aftermarket wheels and tires.
The rotation may be higher, but the profile sizes are where you want to be careful. You’re still running correctly at 50 front 45 rear, the trouble starts when you try to run same profile front to rear or higher in the rear vs front, although most manufacturers engineer up to a 10-15% variance built in for such situations for aftermarket wheels and tires.
Just want to be clear, are you stating, from an engineering perspective, that the rears being slightly smaller still fits within the 10-15% tolerance levels? The rotational difference is equivalent to:
751 (front) vs 746 (rear) or 5 revs per mile difference, with the rears having 5 fewer revs per mile.
I just picked up a 2014 is250 awd
wondering if I put a motorized head unit in the bottom (replace cd player) if I'll lose media info on the oem screen and dash panel screen? I know I can get the steering wheel controls working, but I assume they're a unit but that's why this is in the dumb questions thread
Thanks
Just want to be clear, are you stating, from an engineering perspective, that the rears being slightly smaller still fits within the 10-15% tolerance levels? The rotational difference is equivalent to:
751 (front) vs 746 (rear) or 5 revs per mile difference, with the rears having 5 fewer revs per mile.
Thank you BTW!
Yes, your setup still fits within the tolerances of the factory transmission. You wouldn’t want the reverse setup, but even at that, you would still be within spec, just on the far negative aspects and not recommended.
Yes, your setup still fits within the tolerances of the factory transmission. You wouldn’t want the reverse setup, but even at that, you would still be within spec, just on the far negative aspects and not recommended.
Você é o cara...tu eres el hombre muy grande!!! You da man...ty!
I remember reading that the torque converter was supposed to lock up in manual mode.
I have a 16 is300 awd. So it's got the 6 speed, and I only feel the tc is locked in 4,5,6. I understand it unlocked in 1 but in 2 and 3 it doesn't feel completely locked, maybe when on throttle it locks but it's definitely unlocked off throttle
Was it only the 8 speed that's locked in all gears other than 1?
I still feel this seems to be one of the most responsive least slushy automatics I've driven, and I'm a mechanic so I drive a lot of cars.
I remember reading that the torque converter was supposed to lock up in manual mode.
I have a 16 is300 awd. So it's got the 6 speed, and I only feel the tc is locked in 4,5,6. I understand it unlocked in 1 but in 2 and 3 it doesn't feel completely locked, maybe when on throttle it locks but it's definitely unlocked off throttle
Was it only the 8 speed that's locked in all gears other than 1?
I still feel this seems to be one of the most responsive least slushy automatics I've driven, and I'm a mechanic so I drive a lot of cars.
Yep, it locks the torque converter, but I think it must be limited by speed or something. It only feels locked if I am at highway speed or if I am accelerating hard. Actually, if you put it in manual mode, floor it, and short shift from 1st to 2nd - let's say around 5500 RPM, you'll notice the shift quality is a little rough. I always thought that had to do with the TC lockup.
If you went up one size in sidewall on all four tires you should be fine. Compare the ratio of stock vs the ratio of your new setup using a calculator. Or compare the difference. An example is Audi allows for slightly more than 3mm difference between front and rear total circumference. If you go slightly over that, likely nothing would happen. Lots of people drive on replaced tires, or worn out tires on one axle. But it would probably start to introduce some additional wear to the driveline over a long period of time the more you exceed that recommended threshold. I skimmed the owners manual and Lexus makes no mention of replacing tires on AWD models.
1. What’s the best brand for the touch up paint for Ultra White 083?
2. I have an ARK full catback exhaust, if I get PPE headers would it make my car pop/backfire more?
3. Any Brembo brakes full set (front and back) for IS 350 F-Sport
Last edited by kevinisbae; Sep 11, 2018 at 04:31 PM.
Instrument panel whirring sound when car starts2014 IS 350 F Sport whirring sound typically occurs on the instrument cluster when car is just turned off and the door is opened, not when car is turned on. What could cause the same whirring sound when car is now being turned on? Sound began at 38.5K miles.
Instrument panel whirring sound when car starts2014 IS 350 F Sport whirring sound typically occurs on the instrument cluster when car is just turned off and the door is opened, not when car is turned on. What could cause the same whirring sound when car is now being turned on? Sound began at 38.5K miles.
Thank you for your help.
38.5k miles? My 2016 IS 300 AWD has been doing that for a while, only has 22k. If I put it in accessory mode, it makes an odd whirring sound for just a moment. Doesn't seem to happen if the car has been running for a while.
Though we might have a different issue. Can you describe where the sound is coming from or post a video?
Does it bother anyone else how when you hold sunroof slide button for a couple seconds to get it to automatically open, but then there's like an extra inch or two it can open more if you press the button again? I wonder what the reasoning behind that is
Does it bother anyone else how when you hold sunroof slide button for a couple seconds to get it to automatically open, but then there's like an extra inch or two it can open more if you press the button again? I wonder what the reasoning behind that is
Reduced wind noise. Someone referenced the car manual.
