Yokohama AVID v4S !! quiet and comparable if not better performance then the stock michelins imo.

 

Yes, I zero odometer A (or both) each fillup. And I top off because where pumps stop is subject to too much variation. So my figures should be very accurate. It's funny...I only occasionally checked MPG with the Grand Cherokee but when I got the Lexus I was initially curious and then just got into the habit of topping off and calculating virtually every fillup, unless I am in a big hurry. I don't keep a log or anything like that; I'm just curious to see each time.

BTW, this is with 87 octane. At some point I really do want to test several tanks of mid-grade or premium and see if MPG goes up enough to make it worthwhile. I should have run that test long ago with the old tires but now I'll wait until I know what to expect with the new tires before conducting that experiment. One variable at a time.

BTW, what pressure is ideal? The official spec, as I recall, is 30 PSI.

 

It is also a good way to keep ahead of possible problems with your vehicle by noting any sudden drops in MPG.

 

Ideal pressure is the manufacturer spec found in the Owner's Manual and door jam. Those values for front and rear are designed to give you the best compromise in ride, quietness, handling, stopping, etc.

Personally, I run 35 PSI all-around in my Alenzas for my time here in FL and highway travels. When in PA, around town, I drop to 32 PSI due to the bad roads. The higher tire pressures provide too rough a ride, IMHO, due to the bad roads and the stiffer sidewalls. Remember, tires are also part of the suspension package.

I have always done this with my street vehicles, running higher tire pressures than spec. Not for fuel savings, rather, I like the stiffer ride. So, a personal preference.

Have not experienced any unexpected wear issues over the years with my original Michelins nor the current Alenzas running these higher tire pressures on my RX.

 

I've been using the FuelLog app on my Android phone. You can add an entry for each fill up and it will give you the mpg for the previous fill up. It also has tons of stats including avg, best and worst fuel consumption and fuel economy, total mileage, total fuel, total costs, total fillups, avg cost per mile, avg cost per gallon, avg cost per fill up, avg miles per dollar, avg cost per month, avg miles per month, avg cost per year and avg miles per year. It's been interesting tracking this info.

 

MPG and speed can change when different tires are installed if the exact oem tire is not installed. You might buy a different mfg tire in the same size but it will differ a bit. you can go to tire rack and look at the specs of the tires and see Rev per mile
this is what tire rack has to say

Revolutions Per Mile

Revolutions per mile indicates the number of times a tire revolves while it covers the distance of one mile. Depending on the tire manufacturer, revolutions per mile may be either measured in a laboratory or derived from calculations based on their previous test experience.

Tire revolutions per mile cannot be calculated by simple math because the tire tread and sidewall bend and stretch (deflect) when the load of the vehicle presses the tire against the road.

Since the resulting loaded or rolling radius is less than half the tire’s published overall diameter (which would only reflect the tire’s unloaded radius), calculating the tire’s absolute rolling circumference isn’t possible.

Additionally, a tire transitions from an unloaded to loaded state as it rolls, continuously flattening where the tread footprint comes into contact with the road. These continuous transitions result in some tread slippage, again increasing the tire revolutions per mile beyond what simple math would indicate.

 

I read thru all the posts and no where do I see anyone mentioning about filing a tire warranty claim on this issue. I too have a 2008 RX350 with original Michelin Energy MXV4 S8 tires and at 40k miles, they are down to the wear bar and dealer has advised me to replace all 4. According to the Michelin warranty booklet that came with the vehicle and also from Michilin customer service, this tire should last up to 6 years under normal driving condition (no mileage warranty on this tire then). During the 1st year, Michelin will replace tires free of charge. After that, they will replace it based on a pro-rated basis based on the wear on your tire. Has anyone ever tried using this approach when replacing your worn tires? Won't this be money ahead since the manufacturer is paying for part of the cost of the new tire as part of the tire warranty (assuming you don't mind having the same brand tires)? Your thoughts and comments please. Thanks

 

Thanks LexusPia for getting us more back on track with the topic.

I wonder if your suggestion would also work for Certified Used with Alenza's as my initial tires (again, not sure if these are OEM or later changed for my vehicle).

 

Typically a manufacturer responds to this claim with a prorated discount off of the MSRP. You can almost always purchase the tire from retail sources at a discount. I don't know of anyone who pays MSRP for a tire so the warranty, when near expiration is virtually worthless, IME.

 

if you dont want the Michelins, I`d go with the yokies.

 

My car drives perfectly straight, but the shops keep pushing the alignment with the purchase of 4 new tires. What's the consensus on alignment?

 

My 'philosophy' is super simple: If, when I change or rotate my tires, there is no uneven wear, it means the alignment is fine. So, there is no need to do an alignment when buying new tires is the old ones wore evenly. I also have noticed that my previous RX had no alignment problems whatsoever through two sets of tires (but, of course, that may depend on what conditions the car encountered during the period)

 

That was my thinking as well. My old tires wore extremely evenly. The Firestone Store installing the new tires did a "free" alignment check and surprise surprise said the rear was off. (Front was in spec they said.) They gave me a printout which said that camber was in spec but toe was off:

Left: 0.35° Right: -0.06°

The specifed range for both (at least according to them) is: 0.04° to 0.19°.

So left is sixteen one-hundreths of a degree off. Right is one tenth of a degree off.

I have no idea if that is significant or not. So far I've taken no action.

Steve

 

The price guide used by Michelin is as follows: "The participating Michelin tire retailer will determine the charge by multiplying the percentage of mileage received by the current selling price at the adjustment location or the price of the tire in the current Michelin Base Price List, whichever is lower. This list is based on a predetermined price intended to fairly represent the actual selling price of the tire". On any tire claim pertaining to original tires, it's best to go thru your local Lexus dealer since other tire retailers are not that interested in processing your claim since you never bought the tires from them and they'll do their best to discourage from filing a claim but instead to sell you a new set of tires.

Our dealer said all Lexus dealers are obligated to assist the car owners to process any tire warranty claim. The rule they have is the tread left on all tires cannot exceed 3/32 at any location (edge or center) before the claim can be filed otherwise Michelin will reject it if the existing treads exceed 3/32. This is the same process regardless of whether the tire comes with a time (e.g. 6 years) or mileage tread wear warranty. If Michelin approves, the dealer said it can save the car owner some money vs buying a set outright on his own. Of course the saving depends on the age of the tire but they said typically about 25 to 30% with this warranty claim. In my case, the dealer measured 3 points on each tire and determined the treads left range from a high of 5/32 to 3/32 which exceed the 3/32 requirement for the warranty claim since all tread depth must be 3/32 or less to qualify so I'll just drive them until this fall which will likely drop to 3/32 or less. The dealer said it is to the advantage of the car owner to try this claim process first since he has nothing to lose but everything to gain. Of all the claims the dealer has filed on behalf of the customers, just about all have come out ahead for the customer but it is more work for the dealer to process the paperwork than just buying a set outright. Hope this helps.

 

thanks sounds like good advice. the tires are wearing evenly so i'll skip the alignment. i'm going this morning for the new tires. decided on the bridgestone dueler alenzas, mostly because they received higher ratings than the michelins on tire rack. i just can't see spending that much for the michelins and then not being happy because they wore out after 20,000 miles.