Mazda 6 Forums banner

Oil Change at 7500 ..is this a joke??

54K views 17 replies 7 participants last post by  DeepCrystal17  
#1 ·
I finally switched from being a Toyo-Honda enthusiast and owner for 22 years, and joined the Zoom-Zoom club.
I bought a new 2017 Mazda6 Touring with the 2 extra packages. Deep Mika Blue and tan leather interior, 19in wheels...this car looks as nice as an Audi A4
this is a Made in Japan car with 6 spd auto which made the difference from my previous cars which now are made in NA/Mexico with lethargic CVT’s , lots of kitch-ish chrome and bland int/ext styling .
First thing I noticed is the oil change interval ( 7500 mi or max 12 mo, per Schedule1 in USA). And when I called the dealer, they said it is every 4000 miles. At $60. Scarry !!!!
I reminded them 0W-20 is synthetic oil, not mineral, but they said it is the Mazda requirement.
Even 7500mi for OC -this is very early, considering that all my previous cars were driven 200K+ miles with no problem changing synth oil religiously at every 10,000miles.
The hot Audi A4 with a Turbo engine has 20,000mi or 2 years interval for oil change.
What is “wrong” with the Skyactiv engine Mazda? It is anything but Sky, as it would keep me on Earth changing oil every 5 mo ( as I drive 1500 miles every mo.)

QUESTION#1: Is 10000 mi for oil change OK with this Engine?

QUESTION#2 there is a location underbody where I can prop my 3.5 tons pneumatic jack and lift the car in case I do my oil change? This car is all plastic covers underneath and I still prefer to DYI… as Hondas and Toyotas were very easy on maintenance allowing to change oil myself.

QUESTION#3. Assuming that I keep receipts of the new oil ( 0W-20 Castrol recommended for maintenance) and new oil filters, and change the oil myself during warranty time ( 5 years/60K miles) at every 7500 miles, will this be considered proof of maintenance in case powertrain problems requiring dealer’s fixing are surfacing during warranty?
Thank you for looking into this
Ron
 
#2 ·
  • Like
Reactions: Byakuya
#4 ·
I think I have the exact same car. Bose/moonroof and LED headlight packages?

Based on UOAs for this engine on bobistheoilguy.com, I'd stick with a maximum of 7,500 as per the manual during the warranty period. Someone did a UOA of a CX-5's 2.5L engine at a 9,800mi OCI and it didn't look great in my opinion (see attached). Viscosities and flashpoint were way below minimums, fuel dilution was 2.5%, TBN was 1.8, iron was over double the average with that engine at 6,300 miles (according to Blackstone). After the warranty, do a UOA yourself before considering pushing out to 10k.

My concern is that Mazda only recommends Mazda brand or Castrol brand oil. So I'd be concerned about using Mobil 1 or similar, something happening to the engine and Mazda trying to deny a warranty claim because you didn't use their recommended brands. You should be able to find decent prices on Castrol but apparently Mazda brand oil is pretty pricey. I like buying NAPA synthetic when it's on sale for <$3 per quart.

Don't listen to the dealer's recommendation for OCI. I'm guessing you probably will pay $50+ at most oil change places since synthetic is mandatory.

There is another thread here with recommended jacking points. There is a Mazda service manual that says it's ok to jack at the forward and rear cross members in centerline of the car. The trouble is most floor jacks won't reach that far under the car, especially in the front. I have free oil changes for the first year so I don't plan to change the oil myself for another 18 months or so, but I would try driving up on 2x6's or something to get the front high enough before you start jacking that the jack will actually fit. Or just get Rhino ramps which are super easy to use.

It is my understanding that any car manufacturer has to accept your receipts as proof of maintenance.
 

Attachments

#6 ·
I've worked in the Automotive field for 16 years, worked for the largest Manufacturer of Auto Parts in the World (6000 employees) as a Sales / Marketing Representative.

I say all that for this, the 3000 mile oil changes are so unnecessary and been irrelevant for almost 20+ years now.

Remember Slick 50? Well they changed the game back in the day to the point it had Oil Companies scrambling. These Oil Companies had it good, they taught consumers that every 3000 an oil change was a must when it wasn't true. They were making Billions off consumer fear.

Slick 50 showed the World that oil can stay in a motor a long time without it actually breaking down. Granted their ploy was it coated metal parts which all they did was insert an additive in regular oil that soaked into the metal (it's the norm now).

The way oil is made these days you can easily go 7,500-10,000 miles. Like picking oil viscosity this will depend on climate, temperature, miles driven per day, city / highway, etc.

If you run Synthetic oil you can drive 15,000 miles with zero issues. Oil Companies now make once a year oil, high mileage oil, we've actually have it good now when it comes to choices.

A 4000 miles oil change is one of the biggest scams in the automotive market.
 
#7 ·
If you run Synthetic oil you can drive 15,000 miles with zero issues.
Really??? What about the UOA I posted where at 9,800 miles viscosity had fallen well below the minimum and fuel dilution had caused flashpoint to fall well below minimum?
 
#10 · (Edited)
Fuel dilution issues are related to two things generally:

1. Problems with the fuel system (a leaking injector, in particular, in an engine with a common fuel rail -- which all DI gas engines are.) This is a SERIOUS issue and if detected needs immediate attention because over time, beyond oil dilution, it will wash down the cylinder walls and result in very high wear rates.

OR

2. A LOT of short-trip, low-temperature operation.

In the second case "don't do that". If you really can't avoid it then you need to dramatically shorten change intervals but your engine life is going to suffer for a whole host of reasons and you ought to consider (seriously) a plug-powered electric -- even a golf cart. Gas engines do not deal well with this because they have to run rich when too cold to run closed-loop. If it doesn't get hot then the fuel never evaporates off and that will lead to dilution problems.

The only place I've ever seen material fuel dilution issues on my engines were on an outboard I owned a number of years ago, and it wasn't leaking fuel. It was just a function of, when it happened, too much low-speed (trolling) operation before I took that particular sample -- I pulled a sample on short hours on that engine a couple months later and it was fine. While I had fuel dilution, in that case, there was no abnormal wear metal readings -- if there had been I would have been testing the injectors immediately.

TBN is not a material issue with gas engines; it is with diesels although less so now with ULSD than it was previously.
 

Attachments

#11 ·
The only place I've ever seen material fuel dilution issues on my engines were on an outboard I owned a number of years ago
So the many UOAs showing flashpoint below acceptable minimum AND prematurely low viscosity don't indicate a fuel dilution issue to you?

TBN is not a material issue with gas engines; it is with diesels although less so now with ULSD than it was previously.
So you don't think it matters that TBN drops from an average of 8 to 1 or lower during the course of an oil's service life in gasoline engines? Zero TBN is not an issue for you? PQIA believes otherwise. Think I'll stick with them.

Resource Room

In an effort to strike a balance, the total base number of a new oil is typically in the range of 7 to 10 for gas engines and 10 to 14 for diesel engines. When the TBN in a used oil drops below 3, it typically indicates the need for an oil change.
 
#14 ·
You ran 8,000 miles on that particular change and from a physical point of view you're still ok. IMHO your insolubles are marginally high. Silicon is high too and while on a new engine that is usually from sealers (rather than dirt ingestion) you have enough time on the engine that it ought to be coming down further and faster.

Does that Focus have a stock air intake and filter and if not did you put the aftermarket one on the car around the time of the first oil change?

Can you go 10k on that oil given your particular service conditions and that report? IMHO, probably. Would I? Probably not, but more because I suspect the insolubles you're accumulating will start causing wear to go up to an unacceptable degree before the TBN will.

YMMV.
 
#15 ·
Oh good, I think we agree now TBN can be an issue.

That was my first Focus and it's long gone. I never ran past 9k OCI with that one or the next one after that UOA. I'll be changing the 6's oil 3 times in the first year to take advantage of the free dealer oil changes. Then I'll run that 3rd change to 7,500 miles and have a UOA done to see if it can go longer in the future. I will be paying extra for the TBN test.
 
  • Like
Reactions: babyluv2
#16 ·
I don't pay for the TBNs on gas engines and never have. I do and have for heavy-duty (e.g. boat) diesels. Then again capacities on those engines are stated in gallons, not quarts, so there's quite a bit more money involved in an oil change, never mind that the overhaul/rebuild costs on those things tend to be the sort of events that ruin your operating budget for the year.

My '03 Jetta has a 1/year 10k/mile published OCI and while I don't have a recent UOA on it (the kid owns it now) I never had any reason to believe it needed to be short-cycled on the OCI when I owned it. It now has in excess of 230k on the drivetrain and I recently did the timing belt on it, which requires removing the valve cover to lock the cam in the correct position. Everything looked good under there with no material amount of wear, sludging or other points of concern. The car has had Rotella T-6 in it since it was new and with the results plus the oil being available at pretty much every WalMart in the country I see no reason to deviate from that. Back when I *did* run UOAs on it Blackstone sent them back by mail so I can't easily just grab one of their emails and post it. :) Assuming she doesn't wreck it or decide to junk it for other reasons I will probably change the oil pump, cam and lifters the next time I do the belt @ 310k miles; it rattles for a couple seconds on a cold start (lifter leakdown) and by then the front main seal will likely be leaking a bit (it's dry now) and it's easy to do the oil pump when you have the front pulley off for the seal. I fully expect that engine to be good for close to 500k before it's truly worn out unless something bad happens (e.g. overheating, etc.)

Oil changes on passenger cars are cheap and modern oils and engines are easily able to run in the 7,500-10k interval range without problems under most service conditions, provided they're in good mechanical shape. If you intend to exceed manufacturer recommendations then you need to back that up with UOAs under your typical operating conditions before doing it.

The problem is that it makes zero economic sense to extend drain intervals on passenger cars; the UOAs required to back it up and know it's ok cost nearly as much as the oil change does, so unless you manage to run double the recommended intervals, which is quite the stretch, you can't even get to break-even. Running "exotic" (and expensive) oils provides no benefit over manufacturer's recommendations either. My usual pattern on a new vehicle is to run three or four OCIs starting pretty much at purchase, then another one around the 100k mile mark for the purpose of establishing what wear levels *should* look like, whether the engine is predisposed to anything stupid (like fuel dilution), along with giving me ammunition to go after the manufacturer on a warranty claim if necessary. If everything looks ok there and I have no reason to be suspicious checking again every 50k or so is usually about as far as I go with it. You can get obsessive with this quite easily but on a car all you're doing, in nearly every case, is draining your wallet.

BTW I have one of the infamous "piston slap" series 5.3L V8s in my '02 Suburban. It checked out fine when new on UOA. It rarely gets driven and yes, at ~70k miles, it clatters some when it's cold if you don't let it sit and warm up a bit first. So no, UOA doesn't *always* catch things that (had I caught it before the warranty ran out) you'd ram up a manufacturer's warranty department. It'll easily make it well beyond 100k though before it blows, and I only need it to haul things occasionally these days (plus it's *waaay* fully depreciated) so I'm not all that cranked off about it. If I was I'd rebuild it but it's not worth the money and effort to do so.

It's an entirely different game with medium and heavy-duty engines simply due to cost reasons both on the oil changes and the consequence of being wrong.
 
#18 ·
The problem is that it makes zero economic sense to extend drain intervals on passenger cars; the UOAs required to back it up and know it's ok cost nearly as much as the oil change does, so unless you manage to run double the recommended intervals, which is quite the stretch, you can't even get to break-even.
Agreed, the UOA's I've done were strictly out of curiosity and to make a positive contribution on those cars' online forums. And since I'm spending half hour - 45 minutes to change it myself it's nice to put if off as long as practical. It was also nice to know that based on the low TBN result I shouldn't have pushed the OCI much past 9k miles.
 
#17 ·
Oil changes

Due to the cold winter climate up here the recommendation is 8K km or 5K miles which were done through the warranty period and now I do 8-10K (km)in winter and 12K Km (7.5K miles) in summer. For winter the block heater is plugged in and the daily drive is 25 minutes each way on the highway so the engine does warm up even if the cabin is still chilly (need heated steering wheel). An additional factor is the sand/dust on the highways is pretty high due to the amount spread for traction from Oct to Mar. Haven't done any oil testing and probably won't but oil is not dropping noticeably between changes. Just hitting 160K Km or 100K miles.