Good afternoon,

My 2011 Mazda 3 2.5S needs an oil change. It's close to 12k and only had one oil change since I bought it new back in May 2011. Have I waited too long ?? My driving habits are pretty relaxed but I drive in Los Angeles traffic and I took it for a cruise in the Malibu Canyons for about 3 months consecutively during the weekends. What are decent or good motor oil brands?? A friend suggested Mobil 1 or Castrol GTX synthetics. Also, does it matter if I put 5w-20 instead of 0w-20? I remember finding a really good thread about the grade of oil but I'm having trouble finding it.

Your help is really appreciated.

Thanks!

 

The factory OCI on my 2009 Mazda3 is 7,500 miles; yours is the same, so unless your first oil change was prior to the 4,500 mile mark, you're not over-due.

As for oil, any discussion about oil is almost sure to generate controversy; that said, here are a few comments:

• If you run conventional oil, stick with OCIs (Oil Change Intervals) no longer than the factory recommendation, shorter would probably be better.
• If you run any grade of synthetic then you can easily stretch the OCI to longer than the factory recommendation; although I would recommend against that practice for the duration of your warranty.
• Your car was designed for 5W-20 oil; using 0W-20 is even better as it will flow better when the engine is first started.
• In my case, I'm now beyond the warranty period, and starting with my next oil change (I've been using Mobil 1 0W-30, yes-yes, I know, my car was also designed for 5W-20), I'm going to run my car at least 10,000 miles for the next oil change. Once I've run the distance I'm going to have a UOA done and I'll post the results.

 

Also for what its worth when you read the owners manual (or sun visor like my truck) and it says NORMAL or SEVERE service 90% of everyone is Severe Service so its best to change the oil on that schedule than the Normal Service one. Drive in a dusty area - Severe, make trips shorter than 10 miles - Severe, frequent idling - Severe, towing - Severe, delivery service - Severe, short trips in winter - Severe. The following would put you in the Normal Service category but if you have even just ONE of the above its still considered Severe: Primarily driven on the highway at highway speeds of 55 mph or higher, the engine is run at least 20 miles each day, the car does not tow or carry heavy loads, oil is allowed to reach and maintain normal operating temperature (200F) to evaporate the fuel and water that is in it from when started cold. Also the design of the engine plays a huge role as well, if your exhaust manifold and pipe go under the oil pan that is extra heat put into your oil that it does not need making it work harder as well. In any case at the VERY least change the oil by what the Normal Service suggests, that will at least give you some protection over not changing it in time.

 

That is also a smart thing to do cause they can tell you how much life your oil has left in it if any and you can adjust your change routine to match, also you can be alerted to a potential failure before something big happens if metals start to climb in the results like tin from bearings or brass from thrust washers or even regular old silica (dirt) from a bad hose/gasket/breather letting in unfiltered air to the crankcase.

 

It was designed for 5w-20?? The oil cap and owner's manual "recommends" 0w-20 for 2.0 and 2.5 liter engines. Thanks for the heads up! Also, I thought synthetic oil is 0w-20? I just read the owner's manual found on the mazda site. https://www.mymazda.com/MusaWeb/pdf/..._Mazda3_OM.pdf. I guess I fall in the schedule 2 maintenance for "driving with extended use of brakes" I assume this is considered driving in stop and go traffic. The category for which scheduled maintenance a vehicle belongs to is found on page 8-3. Scheduled 2 vehicles states to change the oil every 5,000 miles. I wish the categories weren't so broad.

I'm a little pissed, I have a coupon to save some dough for synthetic oil at the mazda dealership but they expired last Saturday. I think they use Orange Line, any thoughts?

On the side note, is it expensive to have an UOA test? I believe they sell test kits for about $30 bucks (first link on google) however I'm not really sure what to read on those tests but I'm sure it comes with a guideline of some sort.

 

Look at www.blackstone-labs.com they give you the kit for free and charge $25 for the Standard Tests to analyze it for you, you can read a sample here Gas Engine Sample Report 1 and when you get your results back post it here and we can help to decipher it for you if you would like

 

an official test would be interesting, though instead of that, i've started doing an oil blot to see how the oil changes as it gets dirty. See Second Opinion: Engine Oil Testing
I'm going to switch to synth for a change and see how long it takes to get dirty & see if it's worth the cost.

 

Yes, your engine was designed to run on 5W-20, and the 2010 Owner's Manual reflects that oil specification; apparently Mazda changed the oil spec for 2011 and later models.

As far as I know, ALL 0W-20 oils are synthetic; that said, I have heard rumblings of a semi-synthetic product that has been in development for some time how, a product that I don't believe has made it to the market just yet.

 

The oil blot test is only useful as a relative comparison test if you use the same make and grade of oil, and if the manufacturer hasn't changed the formula. The thing is, different oils use different base stocks and additives, and some of those additives naturally darken after only a few thousand miles of use. Case in point, Mobil 1 is well known for turning nearly black after only a few thousand miles.

FWIW, the first UOA I ever ran was on a previous car which called for a 7,500 mile OCI, the oil sample (Mobil 1) I sent in had just shy of 7,500 miles on it and was black-black-BLACK. The results came back with extremely low particulate matter, and an additive score which indicated the oil was good-to-go for several thousand additional miles. The next sample I sent in from that same car (using the same oil) was after 11,500 miles of use, and it still came back showing low particulate counts and just enough additives remaining to last beyond the 12,000 mile mark.

From that point on my OCI for that car (and the other one we had just like it) was 12,000 miles. When I sold both vehicles (several years apart) they each had somewhere north of 170,000 mile showing on the clock, and both engines ran as well as the day we drove them off the showroom floor.

 

You likely didn't cause any lasting harm to the engine, though if's possible this change may be dirtier than later ones as more metal shavings end up in the oil in the first couple of changes.