Tires Tires Tires

[NeoN]

any updates since aug? I'm interested in purcahasing a set of the Yokohama Prada Spec X tires for $150 a piece,

[jkatsoudas]

Many thanks to everyone who's contributed to this thread, and to RXREY's tire thread. I was driving along the freeway the other day and a truck in front of me dropped a ladder in the road. It was rush hour, so swerving into another lane to avoid it was out of the question. The best I could do was get far enough over so that I only ran over it with the two left-side wheels. Both suffered cuts in the sidewalls, though only one started leaking. That one held air long enough that I was able to get off the freeway before the low tire pressure indicator came on. Long story short- I put a set of Bridgestone Alenza's in 255/55 R18 on the car yesterday. It's been raining a lot here lately so I have no interest in testing their handling characteristics at the moment, but my initial impression is that they are a lot smoother and quieter than the Michelins they replaced (and I think they look nicer too).

As I pondered this decision the other night and was debating whether I wanted to go with the larger tire size or not (and the associated speedo error) I decided I'd do a quick test. Since I had the old tires on the car, I reset the odometer and took a measurement on my commute to work. the odometer, with the original tires, put the trip at 15.0 miles. Two independent sources:

http://www.mapmyride.com/

and

http://www.gmap-pedometer.com/

put the trip at 15.3 miles. I then put the new tires on and retested today and got 14.7 miles. So, this tells me that the new tires introduce some additional error, but that there was already error present with the original tires. A quick calculation puts the error at 3.9% with the new tires, up from 2.0% with the old tires. This translates to an error of 2.5mph (low) at 65mph, or an error of 2,500 miles low on the odometer over 100,000 miles. Not a huge deal in my book. Nonetheless, I'm still looking into ways to calibrate the speedo. Calls into the local dealership parts/service department and to Lexus corporate have yielded nothing, as the canned response is that Lexus does not recommend modifications to the vehicle, including the installation of non-factory sized tires. On my old Bronco I was able to replace a $5 plastic speedo drive gear with a different ratio to compenstate for larger tires. I'm still investigating whether such a part exists for this vehicle, or whether there's a computer adjustment that's possible. I'll post if I come across anything.

[NeoN]

Many thanks to everyone who's contributed to this thread, and to RXREY's tire thread. I was driving along the freeway the other day and a truck in front of me dropped a ladder in the road. It was rush hour, so swerving into another lane to avoid it was out of the question. The best I could do was get far enough over so that I only ran over it with the two left-side wheels. Both suffered cuts in the sidewalls, though only one started leaking. That one held air long enough that I was able to get off the freeway before the low tire pressure indicator came on. Long story short- I put a set of Bridgestone Alenza's in 255/55 R18 on the car yesterday. It's been raining a lot here lately so I have no interest in testing their handling characteristics at the moment, but my initial impression is that they are a lot smoother and quieter than the Michelins they replaced (and I think they look nicer too).

As I pondered this decision the other night and was debating whether I wanted to go with the larger tire size or not (and the associated speedo error) I decided I'd do a quick test. Since I had the old tires on the car, I reset the odometer and took a measurement on my commute to work. the odometer, with the original tires, put the trip at 15.0 miles. Two independent sources:

http://www.mapmyride.com/

and

http://www.gmap-pedometer.com/

put the trip at 15.3 miles. I then put the new tires on and retested today and got 14.7 miles. So, this tells me that the new tires introduce some additional error, but that there was already error present with the original tires. A quick calculation puts the error at 3.9% with the new tires, up from 2.0% with the old tires. This translates to an error of 2.5mph (low) at 65mph, or an error of 2,500 miles low on the odometer over 100,000 miles. Not a huge deal in my book. Nonetheless, I'm still looking into ways to calibrate the speedo. Calls into the local dealership parts/service department and to Lexus corporate have yielded nothing, as the canned response is that Lexus does not recommend modifications to the vehicle, including the installation of non-factory sized tires. On my old Bronco I was able to replace a $5 plastic speedo drive gear with a different ratio to compenstate for larger tires. I'm still investigating whether such a part exists for this vehicle, or whether there's a computer adjustment that's possible. I'll post if I come across anything.

hey so how do you like the tires so far? try a local tire shop or auto repair shop see if they can do anything for your speedo.

[NeoN]

These tires are wider and larger than the OEM tires and due to suspension geometry there was some interference when installing them.

The rear tire rubs against one of the screw heads the secure the plastic fender well lining. This only temporary as when weight is put on the suspension, the tire quickly moves out and up, away from the interference. So, unless I become airborne, this is not an issue.

The clearance behind the tire to the rear shock tower is tight. Any mud or snow that attach's to the tire will definitely be scraped off by the tower. There is NO room for rear chains, but that is true of the OEM tires as well.

I have also noticed that when turning lock to lock going forward I can hear a slight bit of rubbing. It only seems to be on the drivers side when turning left, but that could be unique to my car's assembly tolerances. The rubbing seems to be with a bit of plastic that extends down from the plastic fender well liner. Not a concern.

So your saying, 255/55/18 is the biggest size you could fit under your RX? is the tire too tall or too wide? would a 255/50 fit better than your 255/55? If your indicating it rubs up against the plastic it seems like your tire is far too tall. I'm assuming I could go with a wider tire but not as tall as yours since im interested in getting 20s on my RX to stiffen up the handling quite a bit.

[jkatsoudas]

These tires are wider and larger than the OEM tires and due to suspension geometry there was some interference when installing them.

The rear tire rubs against one of the screw heads the secure the plastic fender well lining. This only temporary as when weight is put on the suspension, the tire quickly moves out and up, away from the interference. So, unless I become airborne, this is not an issue.

The clearance behind the tire to the rear shock tower is tight. Any mud or snow that attach's to the tire will definitely be scraped off by the tower. There is NO room for rear chains, but that is true of the OEM tires as well.

I have also noticed that when turning lock to lock going forward I can hear a slight bit of rubbing. It only seems to be on the drivers side when turning left, but that could be unique to my car's assembly tolerances. The rubbing seems to be with a bit of plastic that extends down from the plastic fender well liner. Not a concern.

So your saying, 255/55/18 is the biggest size you could fit under your RX? is the tire too tall or too wide? would a 255/50 fit better than your 255/55? If your indicating it rubs up against the plastic it seems like your tire is far too tall. I'm assuming I could go with a wider tire but not as tall as yours since im interested in getting 20s on my RX to stiffen up the handling quite a bit.

I'd agree with Skyfish that there's no room for anything taller than a 255/55/18 in the fenderwell, but I haven't experienced any rubbing with my 255/55 Alenzas. A 255/50 would have a bit more clearance, and would be identical diameter to the factory 235/55 so there wouldn't be any increase in speedo error, but there are only two tires made in a 255/50 that I could find. They are both Pirelli and they are both supposedly summer performance tires so they didn't meet my needs. Also, on a 7" wide rim, the 255/55's have a fair bit of sidewall angling to fit on the narrow rim (this size is supposed to be on an 8" rim) and the shop had a bit of a hard time getting the bead to pop into position, so a 255/50 would likely be even harder to get on that rim (just speculation on my part). No idea what effect, if any, this would have on driveability.

[NeoN]

These tires are wider and larger than the OEM tires and due to suspension geometry there was some interference when installing them.

The rear tire rubs against one of the screw heads the secure the plastic fender well lining. This only temporary as when weight is put on the suspension, the tire quickly moves out and up, away from the interference. So, unless I become airborne, this is not an issue.

The clearance behind the tire to the rear shock tower is tight. Any mud or snow that attach's to the tire will definitely be scraped off by the tower. There is NO room for rear chains, but that is true of the OEM tires as well.

I have also noticed that when turning lock to lock going forward I can hear a slight bit of rubbing. It only seems to be on the drivers side when turning left, but that could be unique to my car's assembly tolerances. The rubbing seems to be with a bit of plastic that extends down from the plastic fender well liner. Not a concern.

So your saying, 255/55/18 is the biggest size you could fit under your RX? is the tire too tall or too wide? would a 255/50 fit better than your 255/55? If your indicating it rubs up against the plastic it seems like your tire is far too tall. I'm assuming I could go with a wider tire but not as tall as yours since im interested in getting 20s on my RX to stiffen up the handling quite a bit.

I'd agree with Skyfish that there's no room for anything taller than a 255/55/18 in the fenderwell, but I haven't experienced any rubbing with my 255/55 Alenzas. A 255/50 would have a bit more clearance, and would be identical diameter to the factory 235/55 so there wouldn't be any increase in speedo error, but there are only two tires made in a 255/50 that I could find. They are both Pirelli and they are both supposedly summer performance tires so they didn't meet my needs. Also, on a 7" wide rim, the 255/55's have a fair bit of sidewall angling to fit on the narrow rim (this size is supposed to be on an 8" rim) and the shop had a bit of a hard time getting the bead to pop into position, so a 255/50 would likely be even harder to get on that rim (just speculation on my part). No idea what effect, if any, this would have on driveability.

no I totally understand, im looking to purchase 20 x 8.5" wheels so it can easily support 255/40/20 tires, however if I can squeeze 275/40/20 on the rim I would love the extra traction. Anyone think an extra 20mm tire would fit?

[jkatsoudas]

no I totally understand, im looking to purchase 20 x 8.5" wheels so it can easily support 255/40/20 tires, however if I can squeeze 275/40/20 on the rim I would love the extra traction. Anyone think an extra 20mm tire would fit?

It would likely stick out past the fenders, based on what I see on my car. Here are a couple of crappy pics I took with my cell phone camera of my car (on the left) with 255/55/18's and another RX with stock 235/55/18's. You can see that the 255's come pretty close to the edge of the fenders, especially in the front.

[RXREY]

I love my 255/55 Toyos. I think it's just enough to make a difference but not too much to create any problems. The rotation is 3% of the Good Year tires that it came with... actually I did the math and it was 3.7% so , (from 746 revs per mile for the GYs to 718 revs per mile for the Toyos) I factor that in when calculating my MPGs. They are wider as well as jkatsoudas mentioned above...and the pictures aren't that bad... they do show the width difference nicely. It's only a little bit of difference but enough for me to like it so much to never go back to the 235/55 size. The car feels so much better and looks more like it's supposed to with the slightly larger tires. The mileage has been the same by the way. If I lost any MPGs, I haven't noticed and it was worth it anyway if I had lost .5 to a full 1MPG. I still get about 26MPG on each tank When the time comes I will get the exact same tires again, Toyo Proxes S/t 255/55/18". Happy trails Lexers, Rey Bustos

[RXREY]

Here's a picture of my 255/55/18" Toyo Proxes S/T s

[NeoN]

no I totally understand, im looking to purchase 20 x 8.5" wheels so it can easily support 255/40/20 tires, however if I can squeeze 275/40/20 on the rim I would love the extra traction. Anyone think an extra 20mm tire would fit?

It would likely stick out past the fenders, based on what I see on my car. Here are a couple of crappy pics I took with my cell phone camera of my car (on the left) with 255/55/18's and another RX with stock 235/55/18's. You can see that the 255's come pretty close to the edge of the fenders, especially in the front.

thanks for the pics. I can see what your saying, how the sidewall sticks out and is extremely close to the fender, im thinking a tire any taller than a 255/55/18 is not a good idea, but 20mm wider I might be able to squeeze out if it is distributed evenly... half (10mm) on the outside fender, half of the 10mm on the inside fender, you get what im saying right? the only thing im worried about is that my wider rim is tucked under my fender more and might rub with the inside of the suspension. I'm not too worried about the tire sticking out but I guess i'll have to compare how the wheel fits with a +35 offset.

[fox4]

Just replaced my Goodyear factory tires (got 35K out of them) with the Bridgestone Alenzas (235/55/18). Had them in play for the last two months in what has been Chicago's 9th worst winter. Lots of snow and ice. Observations - on dry pavement performance/handling equal to or slightly better than the OE Goodyear Tires. Mileage about the same - maybe slightly better. However, when on wet pavement the tires stick like glue. In snow up to 10" the RX400h didn't even hesitate - just went right on through. Got out of my driveway after the plows put more snow on it that the weather without a loss of traction. Braking and acceleration were as close to normal as you could reasonably expect in snow. On ice - I actually had some traction. In a word - terrific. No regrets.

No complaints on the the RX400h AWD system either - winter or summer. We rent a house in Michigan in the summer with a driveway made of semi loose asphalt that has at least a 45 degree slope - maybe more. It requires a 90 degree left turn about a third of the way up so you have to slow down. Every year it's a crap shoot whether the rental car will make it to the top at least once so we can unload and again to pack up. Last summer, the 400h, even with the OE Goodyears made it up without even a strain. This year with the Alenzas, it should be even easier.

[NeoN]

Just replaced my Goodyear factory tires (got 35K out of them) with the Bridgestone Alenzas (235/55/18). Had them in play for the last two months in what has been Chicago's 9th worst winter. Lots of snow and ice. Observations - on dry pavement performance/handling equal to or slightly better than the OE Goodyear Tires. Mileage about the same - maybe slightly better. However, when on wet pavement the tires stick like glue. In snow up to 10" the RX400h didn't even hesitate - just went right on through. Got out of my driveway after the plows put more snow on it that the weather without a loss of traction. Braking and acceleration were as close to normal as you could reasonably expect in snow. On ice - I actually had some traction. In a word - terrific. No regrets.

No complaints on the the RX400h AWD system either - winter or summer. We rent a house in Michigan in the summer with a driveway made of semi loose asphalt that has at least a 45 degree slope - maybe more. It requires a 90 degree left turn about a third of the way up so you have to slow down. Every year it's a crap shoot whether the rental car will make it to the top at least once so we can unload and again to pack up. Last summer, the 400h, even with the OE Goodyears made it up without even a strain. This year with the Alenzas, it should be even easier.

thats great to hear, i just wish lexus would listen up and give us the alenzas as a factory option instead of the garbage good years and michilens

[RX400h]

The Alenzas are excellent tires. We've had them on for 10,000 miles now and they still look new. Traction is great, dry or wet and at $600 per set, they represent a very good value.

[NeoN]

http://cgi.ebay.com/ebaymotors/ws/eBayISAP...sid=p2759.l1259

I just found 22" wheels on an RX400h!!! 265/35 tires, wow this blows a hole wide open in my search now I can probably fit 275/40/20 on my car if i tried and the 22's cost $500 to ship in the auction so forget about that but 22's on an RX, wow!!

[RX400h]

40-series on an SUV???? Be prepared for a kidney-pulverizing ride!!!!

[NeoN]

40-series on an SUV???? Be prepared for a kidney-pulverizing ride!!!!

lol the suspension is so soft im not too worried. I ride with 285/30 on my supra and its not bad at all since I have the in-car shock stiffness control :)

[flybones]

I'm new to the forum, but we've had our '06 RX400h since new, now with 24K miles. We had an interesting tire experience with the dealer when purchasing the car. The demo we drove had the OEM Michelins and we were fine with that, but when (some months later) our car was delivered it came with the GY Eagle RS. This tire had very poor owner reviews on Tire Rack and when we pointed this out to the dealer he actually swapped out our tires for Michelins! I thought this was uncommonly accommodating. We have had good service from them here in New England, but run them at significantly hicher pressures than recommended to prevent rounding off the outside corners--currently 40F/36R. What are others using for pressure?

[RX400h]

I have been running 35 psi all-around and after more than 10,000 miles, have found wear to be very even.