What is the deal with the owner's manual stating that 5W20 oil should be used year round in the Mazda5?

I thought 5W20 was only supposed to be used in places where the temperatures were never above 50 degrees F...

 

where exactly would you get 5w20. Not exactly a common grade of oil (at least around here) 0w30, 5w30 , 10w30 are popular, but 5w20??

 

I'm guessing it can be purchased at the Mazda retailer's service department...

I'm pretty sure I've seen it at Walmart too... I'll have to check again next time I'm there.

 

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 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?

 

The primary reason for 5W-20 is for fuel economy so do not worry about the use of the 10w-30. It is a slightly heavier oil but most definitely not enough to cause you any problems Caprice. And voiding your warranty is a pile of you know what. 5W-20 is recommend for use in pretty much all later model Mazda's. I think the number I heard was that it will help to increase your fuel economy by between 1/4 to 1/2 of 1%. Sounds piddly to you and me but when you multiply that savings by say 1 or 2 million cars it raises the fleet consumption rating overall for Mazda to claim to the EPA.

 

You might run into an issue if you have a warranty clain later and this invoice surfaces. I would go back to the place that invoiced you incorrectly and complain bitterly until they recify the situation and warrant that they did in face use the correct grade of oil (written please) The only negaive thing I've heard about Mazda is that they are really particular that you follow the warranty program EXACTLY!!!!

 

Regarding the new spec of 5w-20.... Check out www.bobistheoilguy.com for lots and lots of unbiased real world results. I think the CAFE rules are bullsh....I mean nonsense. Never the less, it seems the latest 20 wt oils really do work, or at least do no overt harm. Check it out and make your own decision.

 

Just a curiosity... if w20 oils are good for the Mazda5, would they be good for my 78 Caprice? I guess what I'm trying to figure out is, if one oil is clearly superior to another, why don't all manufacturers use it?

 

Probably not. The toloerances on you 78 will be... More open. You might see the oil being burned as it's a l;ighter weight. My brother-in-law has an old Toyota Camry wagon (in Australia) with 350000kms on it and his Mechanic has him using straight 50w oil to buy him some time.. Doesn't have the funds for a rebuild! and doesn't want to rebuild . So my guess is the thicker oil doesn't blow by the rings, at the same time You wouldn't want the thinner oil to start doing the same thing in your Caprice that could cause other problems to start.

 

5W20 started to be used in the late 90s to increase fuel mileage. Ford and Honda was among the first to use it. Since the only oil you could get in 5W20 outside of the dealer was Motorcraft, I used Motorcraft 5w20 for the break in and switched to Mobil 1 5W30. I did this with a new Honda Civic, New Honda Accord, and 2 Ford Expeditions and had no problems whatsoever.

Matt