Synthetic oil change every 3k?

desertmike680

Member
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06 MazdaSpeed 6
With our turbo engines, is it really necessary to get our synthetic oil changed every 3k? I heard from one person being that its a turbo motor, that yes it should be. And I heard from some one else that it could get changed every 4,500 miles. But, its with the exception that synthetic is used. In which, I have never used regular oil in the Speed 6.
 
Owners manual says every 7500 miles for normal driving, or 5000 for heavy duty driving. The more frequently you change your oil, the more resistant to fuel shearing (and hurting the viscosity) of the oil you'll be.

It certainly won't hurt to do that, but look into doing a used oil analysis after a 3k change. You may find that the oil can go longer and not break down beyond a reasonable level.
 
i've had my rotella t-syn 5w40 testing by blackstone when it had 4k on it and they said i could have gone another 1.5-2k miles.
 
I try to change my Penzoil Platinum between 4 and 5,000 miles. Haven't done an UOA though, maybe next time just for interest and security.
 
I did some research into this a while back. 3500 miles is a myth perpetuated by the oil change industry and supported by fifty-year-old science. Back then, 3500 miles was necessary because checmical engineering wasn't what it is today.

A good modern conventional oil will last upward of 7500 miles. A good synthetic will last 10,000 and some will even go 15,000.

That being said, I drive the !@#$ out of my car. I follow Mazda's recommended interval but, with synthetic. Every 7500. I figure that is more than safe.

Semi trucks also have turbos and they don't change their oil nearly that often.

If you're worried, there are companies who sell oil analysis services. You can send them a sample of your old oil and they will tell you things like particulate count, metalic ratios, breakdown, etc.
 
I change with amsoil every 2500-3000 miles. Fuel dilution of the DI is to blame.
 
I change with amsoil every 2500-3000 miles. Fuel dilution of the DI is to blame.

Thats why I change mine every 3k as well. Towards the end of the oil change you can start to smell the fuel in the oil!!! Thats on a MSP. I can only imagine on how bad it is on the MS3 or MS6.
 
i typically change mine about 4-5k. i figure if the car manufacturer tells you to do it every 5 under extreme circumstances, then thats sufficient. they would make more money for the dealerships if they told you to get them more frequently.
 
I use royal purple and I change it every 5k, but my motor is na, so that makes a big difference.

On extended drain intervals it is the dirt in the filter that helps to degrade the oil. Most oil manufacturers recommend a filter change and a top off halfway to the extended interval. If you are doing 6k it is recommended to change the filter at 3k...
 
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Well I have heard from a bunch of different people that 4-5k is typical for synthetic. However, with all the heat in Vegas, I try to keep it as close to 3k as possible. Gotta take environment into account as well, since all that summer heat is harder on the engine. :p

EDIT:

I use Mobile One Fully Synthetic 5w 30. My other friends use this as well in Vegas (twin turbo applications), and one even just got a Mobil one synthetic product guaranteed to last up to 15,000 miles. Definitely ranges.
 
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I use Mobile One Fully Synthetic 5w 30.

I use Mobile 1 also, and I change it every 3,000 miles. I also don't drive much, so I find myself getting an oil change every 6 months... longer than it should be time wise, but it's usually only 2,500 to 3,000 miles after 6 months or so.
 
I use Castrol Edge 10w-30 full synthetic. Costs me $50 for the oil and Mobil1 filter.

Change every 3,000mi on the dot.
 
The way i see it, the more often you change it, the more your car will like you. Performance wise, how long it lasts you wise, every wise. I treat mine like a baby. every 2500-3000 miles with full synthetic. Every once in a while, i treat her to royal purple. :)
 
Why are you guys using 10w-30 in the first place?

For those of you changing your oil every 3k, please take a second and read the owners manual. On a normal driving schedule, you change oil every 7500 miles, and on a heavy driving schedule, you change it every 5000 miles. I think you might want to look into a UOA and find out how your oil is holding up and adjust your intervals accordingly. I'm going with Amsoil Euro 5w-40 and changing it every 5000, and the UOA I had done said that it still had some life left, but had started to dilute from fuel shear. Unless you're letting it sit and only putting 3k every 6 months on the car, you're wasting your time and money IMO.
 
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