Synthetic Motor Oil Change Interval
 

Now that new car companies are pushing 5000 miles between oil changes with standard 5w-30 blend oil what is the oil change interval for a full synthetic like the Mobil-1 0w-20?

I don't know, but both of my Hondas (1996 and 2004) specify 7,500 miles between changes. I've changed to a 10,000-mile interval with synthetic now.

If you change less often then acids will build up more in the oil.

http://www.oilanalysis.org.uk/analysisacidity.html

Having the used oil analyzed would tell you if there is going to be a problem.

I highly recommend this forum:
http://www.bobistheoilguy.com/forums/ubbthreads.php

It has all the answers wrt to oil. Ask a model specific question wrt to your car and you should get a good interval based on others experience.

I use

http://www.blackstone-labs.com/

for oil analysis, I just haven't gotten around to sending in my oil

7500 miles seems like a great mileage for all oil changes synthetic or petrolium. I always went 7500 mile intervals with no problems. Draining at 3000 miles seemed like a waste of good oil when it comes out clean and the oil at 7500 just "looked" right to me.

Yes, BITOG (BobIsTheOilGuy) is an excellent forum for all things automotive that have to deal with fuel and lubricants.

The best short answer is there is no perfect short answer. I saw one oil analysis of a late-model Honda that used the on-board oil-life-monitor system to let him know when he should change his oil. For those of us that regularly get UOAs done (I too use Blackstone Labs) we thought the oil had been pushed too far. It was not a catastrophic result, but what’s the sense in trying to save $10 per year by pushing oil changes out 20% too long?

If you live in an area of the country that is very moist, sees extremes of hot and cold and/or you make frequent short trips, it’s a good idea to change it a bit more frequently. The OLM takes some of these things into account … but then makes a judgement I don’t agree with.

Without UOAs, I’d use 6,000 miles for a “conventional” motor oil and 8,000 for a synthetic such as Mobil 1, Amsoil, Pennzoil Platinum, Castrol Syntec, etc …

6k on the Jeep, once the Insight comes online, it'll see 7-10k changes

Whatever you do, please don't waste Mobil 1 by draining it at 3,000 miles. Don't go any less than 5,000 unless there are known problems with the engine.

Even if you buy the cheapest motor oil you can get your hands on, it will still do fine in 5k intervals.

I ask because I was going for 10K intervals, but many have told me I can go to 15K with no problems. This vibe runs great and has 36K miles on it, I got it with 10K. So I will likely stretch to 10K until evidence proves to the contrary ..

If it was my car, I would get the oil analyzed at 10K if I was going to go that far or more. That's the only "evidence" you're going to find. Otherwise, you wouldn't know when the oil was degraded to the point of damaging your engine. While M1 may be able to protect Engine A for 10k, it may only be enough to protect Engine B for 7,500.

Pennzoil Platinum is a cheaper and I think better alternative to M1. A quick search on the BITOG forums will answer any questions.

Boutique oils like Amsoil (which I'm currently using) have specific oils meant for extended drain intervals. The one I'm using advertises 35,000 miles normal service and 17,500 severe service, though I take it with a grain of salt. It's quite expensive, and only worth the money if you decide to follow their schedule (in which case you would save money).

Does your car have the same Toyota 1.8L 1ZZ-FE as newer Vibes and Corollas? Here is a Used Oil Analysis of an '06 Vibe with 7500+ miles on Havoline synthetic. Results look perfectly okay.

if its mostly highway go 5k and change the filter and top it off,, full service a 10k

I'm using amsoil 0w30 in the saturn. I wouldn't go over 10k without a UOA either. I run 0w20 in cooler weather.

I usually change mine at around 5k.

But don't ask about oil brands, that's like asking what religion everyone is a part of because everyone is so crazy about who's is the best oil LOL!

Some really cool stuff on oil analysis at this site:

http://www.bobistheoilguy.com/

royal purple advertizes 12k intervel

"Royal Purple advertises 12k interval."

They also would have you believe that Iron Man uses their oil. :rolleyes: