donRX400h

I just received this email from Michelin today regarding a question about the Latitude HP for the Porche - Part Number 26669 (Why are the revs per mile higher than the stock 235/55-18 yet the overall diameter is larger?): You helped us discover a mistake that we had on our Web site pertaining to the Michelin Latitude Tour HP in size 255/55R18 109V XL (Part Number 26669). The overall diameter is actually 28.03 inches, not 29.1 like the P255/55R18 104H (Part Number 03727, rev per mile is 720). That is the reason the rev per mile is greater (742) on the Porche tire compared with stock Lexus size 235/55R18 (736). If you really want a sporty RX400H that is probably the tire to go with. It is slightly lower than the stock tire and is the widest that will fit (10.43 wide). I still plan on going with the 255/55R18 104H (Part Number 03727) because: 1. I prefer a little more tire protection from curbs and 1 inch could make the difference 2. I want the tires to last longer than the V rated Porche tire 3. The price is $240 compared to the Porche tire, which is over $300 4. I like the look of a fuller wheel well 5. I can deal with the speedo reading 67 when I am going 65 6. The 104H is probably overkill for the RX400H anyway

Thank you everyone for points of view. Choosing a tire that you will drive for about 3 years is a very important issue. I have researched this very carefully. From all the online research I have done, the Michelin Latitude HP 255/55-18 seems to be the highest quality tire that fits a 2006-2009 RX 400H. I did see negative issues with tires that fit the RX400 from Toyo, Goodyear and others and could find only positive reviews on Michelin. Discount Tire also said they have had the best satisfaction level from the Latitude HP. There are several 255/55-18 Latitude HP tires from Michelin available. I narrowed it down to two that have the closest size specifications to the stock 235/55-18 (28.3 inches in overall diameter). I thought it would be best to get an answer directly from Michelin. My Question to Michelin: The performance package comes with the 235/55-18, which is a V with a 99 load. As I mentioned in the last email, the Latitude HP made for the Acura MDX has an even higher load of 104. The Acura H is rated to 130 where the stock RX400 17 inch S is only to 112. So, based on that info...do you think the Acura 03727 (255/55-18, 104H) tire is better for the Lexus RX400h or is the Porsche 26669 (255/55-18, 109V) is better? It seems to me that Porsche tire might be overkill but you guys are the tire experts so I am counting on your guidance. Michelin Answer: Assuming there are no clearance issues within the wheel wells, the Latitude Tour HP in size 255/55R18 104H (29.1 inches tall and 10.3 inches wide - Part Number 03727) or 109V (29 inches tall and 10.43 inches wide - Part Number 26669) may be an option. The Latitude Tour HP in size P255/55R18 104H would provide a comfortable ride and high performance handling. If you are looking for higher performance handling, then you may want to consider the Porsche version in size 255/55R18 109V XL. This tread design should provide even tighter responsiveness and steering wheel control, not to mention an even greater load carrying capacity. Of the two designs, the H-rated version may tend to last longer in regard to tread life. I am going with the 104H and should have them on this week. I'll post before and after shots too. Don

Thanks. I appreciate the input and will go with the V. The Goodyear costs a lot less...$198 vs. $268 each for the Latitude HP. They have nearly the same specs and the Goodyear also has a 50K warranty. Decision is getting easier. How quiet are the Goodyear tires and have you noticed any drop in MPG? I am getting about 28 MPG with mixed driving.

Okay...I hate math. So now I know the smaller size doesn't impact warranty, which is great. Thank you! I was also going to the 255/55-18 for a little more rim protection from curbs and little fuller wheel well. I did this on an RX 300 and it improved the look. I guess my only question for Skyfish or anyone else that really knows tires is the question about the Acura MDX 104H tire making that big a difference over a V tire. The Porche V tire is very close to the same size so that could work...Tire Size: 255/55R18/XL (MSPN: 26669). Just more money, what is another $100 when you ride on them for 40+K right (hopefully)! The Acura MDX just seems like such a similar car to the 400h than the Porche does.

Okay, great. Thanks for the quick response. Here is my concern: If I go with the 255/50-18 I will gain more miles since the tires are smaller, spin at higher REVS than the OEM and then I will be out of warranty sooner. The 255/55-18 for the ACURA has a higher load rating on the Latitude HP (104) than the Lexus OEM at 99. There are lots of Acura's here in AZ with those tires and it weighs 4451 lbs. compared to the RX 400h at 4190 lbs., so it seemed to make sense. The Latitude HP for the Mercedes is a 105V tire but is also 10.6 wide instead of 10.4 and also has a OD of 29.2 instead of 29.1. There is a Latitude HP for the Porche that is 109V and 29 OD and 10.43 wide. Soooo many choices!!! I did see that RXRey has had the TOYO Proxes for over 14 months with no problem but felt the Michelin might be the best quality. What is another $200 when you spend over $45K on the vehicle, especially on something that will last for about 3 years. Your thoughts?

I am at 30 K and the Michelin Energy MXV4 are almost toast. I have heard good things about the Michelin Latitude HP and was going with the 255/55-18 104H, which is designed for the ACURA MDX. I like the look of the TOYO so was considering that too, but they are just a bit larger in overall diameter than the Latitude. Has anyone tried the Latitude HP? Nothing but sunshine in AZ so ride quality is my number one concern. Also Rey, where did you get the front spoiler and how much was it? It makes the front end look more solid, I like it. Don

You can run 255/55VR18, 245/55VR18, or 255/50VR18 tires on your OEM wheels without any safety issues. Be sure the load rating is at least 99 and do not drop down to lower speed ratings like H. Some minor rubbing in hard cornering may be found for the larger of those, but if you are doing that with your family in the car... then you really aren't that concerned about safety are you? Your safest bet if you don't want to take any risk is to just get the the OEM tire size. The Bridgestone Dueler H/L Alenza is your tire of choice for this size. CAUTION: I would avoid wheel spacers as they change the way loads are transfered from the wheel to the hub. These OEM wheels are desinged to fit over a feature on the hub so that the wheel bolts are only in tension (no shear loading). If you install spacers, this function is lost and the wheel bolts now have to carry tension AND shear loads. They were not designed for this. This is a REAL safety issue. To move to wider tires without any clearance issues or spacers you will need to get different rims that have a greater offset from the hub. Just be certain thay engage the shear feature on the hub in the same way the OEM wheels do, or you will be placing the botls in shear again. Good Hunting. Sounds like you know what you are talking about! After much research, I am planning on going with the Michelin Latitude HP 255/55-18 104H, which is what comes standard on the Acura MDX. It has the closest overall diameter of any 255/55-18 tire so it makes it closer to the stock OD. I never go over 75MPH so I didn't think the H mattered and the MDX seems like a very similar SUV.

I have amazing tires on my 400h. Toyo S/T Poxes 255/55 18". I have had them for a year and a half ,15k miles,and show very little wear and NEVER have they rubbed. The slightly bigger size makes the car look so much better. It fills the well a tad more but enough to make it very apparent that the car seems it should have been placed on 255/55 tires. Anyway I've really been happy with them. They look great,feel great and handle great....well, they ARE great...sorry for the fourth grade level review but I really love them! I have a bunch of pictures on the post that I placed, "Best tires when it comes time". I believe that its still on this first page of posts. Good luck but you'll be happy to get anything than what the car comes with. At least you got some miles from your Michellins, I got 11K out of the crummy Good Years! Rey Thanks Rey and everyone...I will probably go with the 255/55/18. The dealer recommended going to the 245/60/18 instead but I, like you Rey, appreciate the aesthetics of a wider tire. Discount Tire now says the tires will probably last until 30 or 35K. I think the last guys at Discount needed to make a sale. Don

I have amazing tires on my 400h. Toyo S/T Poxes 255/55 18". I have had them for a year and a half ,15k miles,and show very little wear and NEVER have they rubbed. The slightly bigger size makes the car look so much better. It fills the well a tad more but enough to make it very apparent that the car seems it should have been placed on 255/55 tires. Anyway I've really been happy with them. They look great,feel great and handle great....well, they ARE great...sorry for the fourth grade level review but I really love them! I have a bunch of pictures on the post that I placed, "Best tires when it comes time". I believe that its still on this first page of posts. Good luck but you'll be happy to get anything than what the car comes with. At least you got some miles from your Michellins, I got 11K out of the crummy Good Years! Rey Thanks Rey and everyone...I will probably go with the 255/55/18. The dealer recommended going to the 245/60/18 instead but I, like you Rey, appreciate the aesthetics of a wider tire. Discount Tire now says the tires will probably last until 30 or 35K. I think the last guys at Discount needed to make a sale. Don

I am at 21K on my RX400h and the Michelins MXV4 S8 only have about 5K left before replacing. Does that seem right? I was getting 65K on my RX 300. Also, I was considering upsizing to 255/55/18 and heard that they will rub on the rear struts from the dealer. Any truth to that. I saw that a few others have used this size on this forum. Lastly, any recommendations for tires? Strictly street and I want to maintain a quiet ride.