2009 subaru outback oil type

I'm a proud new owner of an 09 OB wagon,70,000 miles, looking to start with a fresh oil change. I'm thinking Amsoil XL-5W-30 and amsoil Filter. I live in CT so see a variety of weather, and don't want to be committed to exactly 3000 for every change. Any input is appreciated!!

There are many opinions on this topic, the vast majority not based on quantitative measurements or objective testing, and thus worth little. With the foregoing caveat I offer this: Run any quality, major brand oil of the type and weight Subaru recommends for your driving conditions and the oil won't limit the life of your car. Don't obsess over this, live your life. Use the recommended model Subaru filter (they're good quality and the only ones I've been able to find that are made to Subaru's ~ 23psi bypass spec. - don't use the Amsoil filter unless they confirm this bypass pressure). It's fine to use conventional oil (provided Subaru specifies it for your engine). The most important things are to allow your engine to warm up a few minutes (easy driving, not idling) before jumping on the throttle, and replacing the oil before it is contaminated or the additive package worn out. The latter will vary with details of your car's condition, service, and the specific oil, but with our 2006 Outback 6cyl. (now 71,000mi.) this appears to be ~ 4500-5000mi. with Subaru's (Idemitsu) 5W30 conventional and 6000mi., maybe a bit more, with both the Subaru synthetic and standard Mobile 1 synthetic (high speed interstate driving, daily 90-100 degree temps. this past summer). If you fear these intervals are too long, consider getting a used oil analysis. Amsoil likely is among the better oils, but I doubt significantly better for normal use, and Mobile 1 and some other main brands also perform well in relevant tests. Over the past 30 years with quality conventional oil in our cars (Volvos, BMW, Honda to over 200kmi) and regular changes none have required oil between changes (4000-5000mi), all remained deposit free. Our Outback (in family since new) did fine on conventional oil for the first 50+kmi., until we switched up to synthetic this summer (mostly for the comparison) - the secret being to change it in time. This summer ours used ~ 1qt/5000mi., conventional or synthetic, but many report higher consumption so check often. For heavy duty service reduce the above intervals.

Change the other fluids at the Subaru recommended time/mileage, maybe sooner with the coolant - change silicate type coolants at <=2 yrs before they gel and organic acid types (Subaru's current offering) at 3yrs (longer for this might be okay, but why risk it, especially with 4cyl models?) Change all fluids of a used car if you don't know its history.

A good reason not to extend oil intervals past 5000-6000mi. (normal driving), even Amsoil, is no matter how good the new oil is it gets contaminated, the additive package wears out, and the only fix is to change it. The better quality synthetics often have lower pour point temperatures and cold viscosities, a true advantage in "real" winters, but several studies have shown that properties like high pressure protection (valuable during cold starts) and high temperature breakdown resistance of the best conventional and synthetic oils are very similar, contrary to advertising hype and differing far less than the range between different brands of either class, so best to avoid discount or lesser known brands of either type. Don't use diesel oils like Shell Rotella, etc, even when also SN or SM rated, as their higher zinc and phosphorous levels reduce catalytic converter life. "Fluids and filters cheap, cars expensive."

Going off topic, Subaru AWD center differentials are sensitive to tire mismatch. Measure the circumference of yours - they all should be the same model and within ~0.25in. circumference, (Subaru's spec. is about twice as tight as other AWD mfgrs.) Flat measuring tapes are easiest to use, you can use a surveyor's tape or just glue or stitch two fiberglass (non-stretch) sewing tapes together. Measure tires and rotate often, maybe every 3000mi. until you get a feel for how evenly yours wear, then perhaps every 5000mi. I've had tires of equal tread depth but significantly different circumferences (same model and date but different mold numbers). Measure and match new tires before mounting - Tire Rack (internet order) will match a set if requested, and also has the means to shave tires to size. Discount Tire/American Tire can shave tires at their main facility, as can some local shops that cater to racers but they may be hard to find. To stay within the circumference spec. you may have to shave a new tire to match the others when replacing just one.