I own a 2003 wrx..I have 20,000 miles on the beast now and have highly considered goign syntyhetic until i saw the price..and i average about 5000 miles a month so my oil changes are fairly frequent.. i was wondering is the synthetic blend (much cheaper) just as good as syntheitc when it comes to thermal breakdown.. and oil coking.. and all that? And i know once u go syntheitc its not recomended to go back to dino oil.. so is syntheitc blend bad?

Dave

There are no problem with switching oil types. Id be more worried about changing brands.

Per mile synthetic oil is very cheap, look how much you spend on gas. Just buying tires with less rolling resistance can offset the cost of the synthetic oil. Driving with your windows up can also offset the cost as well as inflating your tires 5 more PSI.

What Im trying to say is to either go cheap, or go all out. Why take the half assed aproach?

Use dino or synthetic. Blends are a waste of money. With the amount of miles you are putting on your car, I'm assuming you are doing a lot of highway cruising. You might consider sending an oil sample of synthetic in for analysis to see how long you can safely go between oil changes. It could be cheaper to run synthetic, after the initial cost of analysis.

Amsoil can be run safely to 10,000 miles or more. I've got 5300 on mine right now.

do your own blend. Who knows how much a blend is really blending.

I buy 4L of dino oil and top up about 1L of synthetic during an oil change.

5qt jug of Mobil 1 Synthetic Oil is $18/bottle at Walmart!! :banana: Cheaper than buying the case of 6 (1 qt bottles). Not sure how many quarts the WRX takes, but for my RS it's about 4-1/4 quarts. So I usually have some extras, just in case I need to top off. I go about 6000 miles per change with no problems. But just to be nice... 4500 miles.:lol:

WRX takes 4.8 qts. A 5 qt. jug is perfect. A little extra so in 2-3 oil changes you can put synthetic in your lawn mower.:lol:

do your own blend. Who knows how much a blend is really blending. Ditto, this way you know your getting somewhere around 20-25% synthetic. That makes a good question, how much is blending for the already blended oil you can buy at the store? I bet it isn't much.

-Charles-