Blog Master G

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Oil Change

Thursday, May 12th, 2005 · 6 Comments

Yesterday after work I picked up from my local Subaru dealership the crushed aluminum oil pan washers that the parts guys failed to give to me the day before when I bought a couple Subaru oil filters. Then it was off to Nat’s place for my 57,415-mile oil change. The last one we did was 3,664 miles ago at 53,751 on February 22. The oil was still very clean, due to our mostly highway driving.

I use Mobil 1 5W-30 synthetic oil. When I first bought the car, I used traditional oil, then switched to snythetic blend for a time, and have been using full synthetic since at least March 5 of this year (33,446 miles) insofar as I can tell by browsing through my service records and own notes.

There’s always debate about how often to change oil. The range seems to be anywhere from 3,000 to 7,500 miles among other WRX drivers who use synthetic, with many folks changing at the 6,000-mile mark. I’ve always tried to stick to every 3,000 miles. It seems to be mostly about peace of mind. Nat changes his WRX oil every 3,000 miles, and James has also always advised me to do the same.

Though I do tend to be pretty obsessive about digital record keeping, I don’t actually have a spreadsheet outlining my WRX service records (gasp!). I do have a combination of notes outlining the last three home-done oil changes, and invoices from all other service records. I don’t have anything as detailed as this guy, but here’s a glimpse at my oil changes since the beginning of 2004:

By shop:
1/7/04 29,926 (standard oil, first NY oil change)
3/5/04 33,446 (switch to synthetic)
5/3/04 37,462
7/9/04 40,752
9/1/04 44,049
10/30/04 47,436

With Nat:
12/18/04 50,300 (approximately)
2/22/05 53,751
5/12/05 57,415

Knowing this, now you can sleep better tonight.

Update: Thanks to Phil’s reminder, I just checked my history at My Subaru and see the following (I used to be better about making my own notes here, but pretty cool that the Subaru dealers do it for you):

Tags: wrx

6 responses so far ↓

  • 1 Jonty // May 12, 2005 at 10:09 am

    Back when I ran my uncle’s auto repair shop, we changed synthetic oil every 5,000 miles. The synthetic stuff can go for up to 7,500, but the oil filter can’t.

    The only major benefit of synthetic is the ability to go longer before changing. If you’re changing every 3,000 miles, then I really don’t know why you’re spending the extra money on the synthetic stuff. Your car doesn’t notice any difference. Trust me.

    Oh, and if you’re thinking that maybe the difference will come when you’ve got 300,000 miles on the engine, and it’s still running, think again. The transmission and everything else in the car will fall apart long before then. =)


  • 2 Gabe A_nderson // May 12, 2005 at 10:31 am

    Turbo car likes snythetic, which not only makes parts last longer, but improves engine performance.

    Also, here’s a great study I just came across (and have added the link to the main part of this entry):

    Long-Term Synthetic Oil Study / Mobil 1 Test esults:

    “Based on the results we’ve got here, we’d recommend 8,000 miles between oil changes on an engine that uses no oil at all, perhaps 10,000 miles on an engine that uses some oil, and 15,000 miles or beyond with a filter change every 5,000 miles. This, of course, isn’t any kind of guarantee, and you must evaluate for yourself what your engine requires. One thing we’re pretty sure about though: 3,000-mile intervals is a huge waste of resources.”

    Perhaps my 3,000-mile intervals are overkill after all!

  • 3 phil // May 12, 2005 at 11:19 am

    Sabaru dealers actually update all the records for you on my But they don’t record the type of oil in your car.

  • 4 Nat // May 12, 2005 at 10:11 pm

    The definitive answer to the oil change debate can be answered with Oil Analysis. Basically you send away your used oil (recently drained) to a lab and they analyze it for contanimation. is an amazing resource to read more about OA. is one of the labs that performs oil analysis. An OA can help you choose an Oil change interval and also pick a specific oil grade as well. I really should do an oil analysis. Untill then, I’ll just keep changing it at 3-3.5k.

  • 5 Sarah // May 16, 2005 at 12:52 pm

    The Car Talk guys on NPR suggest 5,000 to cut back on the waste & pollution. All that changed oil needs to be “dumped” somewhere.

  • 6 Nat // May 18, 2005 at 11:25 am

    Good Point Sarah! That is why I take my oil (and Gabe’s) to a recycling center where it can be refined and reused. If you bring your car to a shop to change the oil, ask to see their oil recyle bin. If they don’t have one, go somewhere else.

    p.s It should be noted, I change my oil so often because my car spends a considerable amount of time at redline at various tracks and autoxs. I follow the factory recommended interval for “harsh or unique” driving conditions.