Keep or exchange new tires?

I just had a set of Michelin Primacy MXV4 195/65R15 tires installed on my 2010 Prius last week at Costco and my mileage has dropped from 44-46 to 38-40. When I purchased the car in 2011 with 39K miles I was getting 48-50mph in the very hilly San Diego area but over time that has dropped down to the 44-46 I was getting with my old tires and I now live in Sacramento which is relatively flat. I have been thinking the mileage drop was because of the higher miles on the car and the age of the tires. When I purchased the tires I wanted the Michelin Energy Saver's but they said it could take a week or longer to get them in and I had a blowout. I went with the Primacy's because they were rated the same for mileage on Michelin's site but everything else was higher like comfort and handling. I was expecting an increase in my mileage because I was running a mix set of Firestone FR380's on one axle and Firestone Affinity Touring on the other and as far as I know they are not LRR rated.

I really do like the comfort and handling of my new tires but the mileage is driving me crazy. The best mileage I have been able to achieve during my daily 60 mile commute was around 44mpg but that required me to drop my cruising speed from 70mph to 60mph but if I drove like that with my old tires I would probably get 50mpg. I also increased the tire pressure to 44F/42R and it maybe gave me 1mpg.

I went to Costco yesterday to see if I could exchange the tires for the energy savers and they said I would need to pay for the mounting and balancing again for the new tires which would be $60. So if you were in my shoes would you keep the Primacy's or exchange them for the Energy Savers and pay the $60? I am having a hard time choosing because I do like the quiet ride I am getting with the new tires but mileage is important because I drive over 400 miles per week. I don't know how much of an mileage improvement the Energy Savers would give over the primacy's. Also beyond tires what else could explain my slow drop in mileage, is it just age?

Also the car now has 89K miles and I change my oil and air filter every 10k miles and I only use Mobil 1 0w20.

 

The price between the Primacy's and Energy Savers was within a few dollars. How is the tire noise with the Energy Savers vs the Primacy's? The ride is of course better with my new tires but the difference in tire noise between my old tires and new is HUGE! I use to think my Prius was silent while driving through a parking lot on electric only but now its dead silent. Its amazing how quiet these tires are and I am hoping the Energy Savers at least comes close.

If the difference after breaking is really 4-5MPG I am going to go ahead with the swap. I really wish I didn't have to pay for the install a second time but nobody in town had the Energy Saver's in stock and that included checking tire rack. If tire rack had them in stock its only a 2 hour drive to their warehouse from Sacramento and I could have driven my wifes minivan to pick them up the same day. I also wanted Michelins because of the $70 off deal at Costco and Costco has free roadside and the install is pretty cheap. I appreciate everyones input.

 

Well I gave the Primacy's another 1000 miles to break in after a trip to San Diego to visit some friends this past week and I could only averaged 44mpg (trip computer) while taking it really easy by never going over 65mph unless I passed someone. I have done this road trip probably around 6 to 7 times with my Prius and I could average around 50mpg while driving 65-70mph on my old tires which comes out as a difference of $9 at $3.65/gal. I went to Costco today to order the Michelin Energy Saver A/S and they ended up being about $10 less per tire so with installation I only had to pay $25. After doing some research I think I am going to fight this. I took a look at the Michelin owners manual from their website and under the section for the 30 day satisfaction guarantee it reads to me that the mounting and balancing is included with the exchange. Here is a copy and paste of the fine print.

"Certain conditions and limitations apply. Exchange available only for the number of tires originally purchased and mounted. Mounting and balancing costs are included on exchanged tires. Valve stems are extra."

Am I reading this correctly because if I am I will ask for my $60 back from the install? I also feel my situation falls under the satisfaction guarantee since I am not happy with the efficiency of the Primacy's even though they are rated the same as the Energy Savers with a score of 10 out of 10.

 

I don't want to be a dick but $60 is not a few dollars to me and especially since my contract at my job just ended this past Tuesday without notice and I am now unemployed. $60 would fill up my tank twice and provide me with 940 miles worth of driving (50mpg @ $3.19/gal) which would be money saved that could help feed my family. Also I didn't ask if it would be worth my time fighting over a refund that as far as I read is owed to me, what I asked is if my interpretation of the fine text makes sense to them. If what I read is correct I am not asking for something that I don't deserve and Costco shouldn't be out any money since I would assume Michelin would refund them the labor and tires since its Michelins tire warranty and guarantee and they are a Michelin dealer.

 

I am not sure if you read my entire thread but its not buyers remorse and I didn't want to exchange them for a different brand. Michelin includes in their warranty a 30 day buyers satisfaction guarantee with their tires so I highly doubt Costco would be out anything and they wouldn't need to worry about selling a used tire.

My original tire choice was the Michelin Energy Saver's but they didn't have them in stock and the according to Michelin's website the Primacy's were rated the same for fuel economy at 10 out of 10 and I assumed if there was a difference in economy it would at most be only 1% to 2%. This wasn't my experience at all and I saw a over 10% reduction in my mileage over my old not LRR tires which I felt wasn't acceptable. I really wish I would have done some research on these forums before the purchase but I was also in a emergency situation since I had a blow out and I have too long of a commute to drive on a spare while waiting for them to receive the tires. I also was told by the Costco tire employee that he has heard nothing but praise for the Primacy's and he has heard of several people complain about the way the Energy Savers handle. This is probably why Costco doesn't keep them in stock since they are probably only popular with people that are willing to sacrifice handling for the highest possible economy.

 

I am sorry but you are 100% incorrect at least for the warranty and guarantee they provide to US customers. Here is a link to the warranty along with a screenshot from their website advertising it.
Tire Warranty | Michelin Tires



Then here are the ratings they provide on their website for both the Primacy's and Energy Saver's. I don't see how someone wouldn't come to the same conclusion that they should provide both provide very similar performance when it comes to economy. Also when looking at the rest of the ratings the Primacy's look by far a better tire over the Energy Saver's.





Yes wanting to exchange my tires was buyers remorse since I regretted my decision but I'm sorry but I feel its Michelins fault since they don't provide accurate ratings for their tires. Also it wasn't like I switched to a different brand because the Energy Savers are also Michelin.