[Tech] Oil change...

[Caprice]

OK... got our first oil change. The manual says use 5w20, the engine's oil cap says to use 5w20, and the service manager at the Mazda dealer we bought the car at (60 miles away) says we will void the warrantee if anything BUT 5w20 is used. The Monro Muffler/Brake place I paid to do the work assures me that they used 5w20, as specified on the filler cap, even though the manager said he didn't see a reason to use that particular oil. That said, the sales draft says 10w30--the manager swears that he entered it wrong.

Is there a way for me to know for sure that the oil is indeed what it should be without draining the thing and starting over? The consistency does seem lighter (dare I say, more watery) than the 10w30 I dump into my Caprice every week or so... would that be an indicator??

Will it do damage to the engine to run on 10w30 for about a month (what it'll take to rack up 3000 miles) if it is indeed the wrong oil? Even thought it isn't likely to be driven in cold conditions (like 5w20 is generally specified for)?

Do I have a problem, even if it is the correct oil, because my sales draft information is incorrect?

[Ballard]

All I can do is give you my personal speculations, but I'm pretty confident these are right.

I think, you did get a bunch of new 10W-30 oil put into your Mazda, and I think it will not be a problem at all in the long run. The only penalty you will pay will be losing point zero one miles per gallon (or something like that) during the next 3,000 miles.

I'm sure the main reason that 5w-20 is spec'd by Mazda is for fuel economy, and only fuel economy. I have never heard any horror stories about oil viscosity causing any real world engine problems in new cars. There has been plenty of talk about "sludge" in some cars like the VW 1.8T, the Toyota 3.0 V6, and the DC 2.7 V6, but those relate to high oil temperature applications that have turned out to do better with synthetic-based oil and have problems with conventional petroleum-based oil. Not directly related to viscosity, and not fixable with thin conventional oil.

The idea of voiding the warrantee over this sounds like alarmist hysteria to me. I bet there are thousands -- tens of thousands even -- of 2005 Mazdas driving around the US and Canada right now, with 10w-30 in them that they got at their first oil change at SpeedyLube.

[7red7]

I'm curious to know when I should do the first oil change...Most new cars I've owned in the past are after the initial 1,000 miles, but the Mazda dealership I got my 5 from said not to change it until I hit 3,000 miles and then again every 5,000 after that...

Is this information in the owners manual??? When did some of you guys get your first oil change???

Thanks!!!

DAN

[Ballard]

From my reading of the owner's manual, the regular maintenance schedule applies right from mile zero. So if you don't fit any of the severe duty criteria, it's OK with Mazda if you wait until 7,500 miles for the first oil change.

It is quite true that in the old days, "break in" was thought to be important. It appears to have become a lot less important in the last decade or two. I don't really know whether this is due to 1. the extinction of an "old wives tale" 2. tighter manufacturing tolerances on parts machining of modern engines 3. better motor oil chemistry 4. other or 5. any combination of the above. I suspect, probably all of the above.

My 5 is my first Mazda ever, but my approach in 30 years of owning VWs Hondas and a Nissan, has been to use Name Brand, correct-viscosity, conventional motor oil, and to change it including the filter about twice as often as the factory specified minimum schedule. That is, 3-4 thousand miles for all my cars. So far, this I think has been extremely successful. I've never had any engine problems, and the dipsticks have all looked pristine (not brown-coated) even at 130,000 miles. I've always traded my cars by about then, but I do know from checking my old VINs in Carfax that at least two of my former cars have made it past 200,000 miles.

[7red7]

Thanks for the feedback...I think I'll just end up changing the oil when I hit 3,000 miles and every 3,000 thereafter...Sound reasonable...I mean afterall, I used to change my oil in those intervals for my old cars anyway...The Mazda dealership around here is fairly priced as well...They only charge 21.00 for an oil and filter change, plus I get a car wash and tire rotation complimentary

[Cwhelly]

The manual specs out oil changes at 8000 KM or 5000 miles..

Clint