Our (independent) mechanic says that my front struts are leaking oil. My 2008 Scion has 27,500 miles and exhibits no driving irregularities. When I push down on the front, it is solid. I have extended warranty and they will pay for new Toyota struts but mechanic is recommending KYB brand which are $447 for 2 vs $278 for Toyota brand. Would I be able to see the oil leak if I could get under the car? Also, checked on line and found KYB front / left suspension kit for $101 and the same price for front / right…is this the same as front struts?
Since you have an extended warranty, I would go with the Toyota OEM parts this time. You can choose KYB vs OEM next time based on warranty, performance, etc.
I don’t own a Scion, but personally I have never had front struts fail on my Toyota Corollas in either 4 years or the low mileage you have. I always though the OEM struts were very good because I don’t recall replacing any when I owned the Corollas, and they both went 200K+ miles.
You may or may not see the leaking struts clearly. If you don’t this opinion, I would find another independent mechanic or suspension shop (not a national chain) and get a free second opinion. Ask them to check out your suspension and see if they arrive at the same conclusion as your regular mechanic.
You might not need new struts - period. In any case, OEM struts are fine and you can get them for nothing under your extended warranty. No brainer, take the car to a Scion dealer, tell them you were told the front struts were bad and leaking. The dealer will check the struts and replace them if they are bad. end of story.
Exactly. Given the choice between “free” and “$400,” the answer is pretty obvious 
The struts are 5 years old and anything is possible but it would be highly unusual for both front struts to fail at such low mileage. Get another opinion.
You do not need to use higher priced struts such as KYB, Bilstein, or what have you even if the failed strut diagnosis is true.
Thank you all for lending experience and common sense to my instincts.
And KYB may, in fact, make the factory struts.
The $$ KYBs are probably high performance and stiffer than OEM struts.
If you put those on with the OEM rear units it will throw off the handling by increasing understeer.
Upgrading the struts can be desirable (did it on my '81 and '88 Accords) but it should be done on all four corners to maintain balanced handling.
The newer generation of struts have a bit of oil seepage and I bet that is what your mechanic has seen. Happened to me on my Camry. We are another 30K miles in it with no signs of failure.
And as mentioned, KYB is the manufacturer of your original Toyota/Scion struts. The more $$ ones might have the sporty/stiffer tuning, but if your car drives fine there is no point.
I will just get the free check done under warranty to be sure.
If the car drives ok, Why the mechanic? Or did he just offer this as a service/boat payment?