Oil change interval with synthetic oil

[Muse]

I just read Ray's bit in the paper (Car Talk, July 14, S.F. Chronicle) on this subject. No mention was made of time intervals, just miles. He affirmed that 10,000 miles is an OK marker for when to change synthetic oil unless you're driving in tougher conditions (real hot, maybe real dirty too).

My car is a 1997 Mazda 626LX 4 cylinder automatic, taking 3.7 quarts of oil. It has less than 31,000 miles on it. I did go a long time between oil changes when I first got the car, and don't know what kind of oil was in it, but then I started doing regular oil changes a few years ago using Mobil 1 Full Synthetic, once a year.

I have only been driving about 1500 miles/year for several years. That could change if I start taking trips. Last year it was less, actually, around 1000. The conditions I drive in aren't very harsh. I climb some hills, the weather is largely pretty mild, never freezes.

Well, should I really be changing my oil and oil filter less frequently than once/year?

 

[jlee]

I would still change the oil annually. Short trips won't evaporate the condensation that builds up in the engine and is carried off by the oil.

 

[Muse]

I would still change the oil annually. Short trips won't evaporate the condensation that builds up in the engine and is carried off by the oil.

Won't taking the occasional ~20 mile trip burn off that moisture in the oil? I was advised to do a 20 miler every 2 weeks or so to keep the car running well. I sometimes go 2+ weeks without starting it up. Don't take a lot of short trips, I use my bicycle or roller skates, weather permitting for short stuff. My car trips very seldom are less than 10 miles, including round trips to Costco every 2 weeks, ~5 miles each way.

 

[agent00f]

I just read Ray's bit in the paper (Car Talk, July 14, S.F. Chronicle) on this subject. No mention was made of time intervals, just miles. He affirmed that 10,000 miles is an OK marker for when to change synthetic oil unless you're driving in tougher conditions (real hot, maybe real dirty too).

My car is a 1997 Mazda 626LX 4 cylinder automatic, taking 3.7 quarts of oil. It has less than 31,000 miles on it. I did go a long time between oil changes when I first got the car, and don't know what kind of oil was in it, but then I started doing regular oil changes a few years ago using Mobil 1 Full Synthetic, once a year.

I have only been driving about 1500 miles/year for several years. That could change if I start taking trips. Last year it was less, actually, around 1000. The conditions I drive in aren't very harsh. I climb some hills, the weather is largely pretty mild, never freezes.

Well, should I really be changing my oil and oil filter less frequently than once/year?

Changing fluids regularly is like stretching before physical exertion, You'll probably be ok without, but warming up lowers risk.

I don't change fluids regularly. Livin on the edge.

 

[clok1966]

The single thing listed time and time again when people with super high mileage cars talk about how they got that many miles. Regular oil changes (almost all list 2 and 3000 miles between) and maintenance. When oil was super expensive I started wondering about it myslef as I have a small fleet (9 cars insured and drove, hey, Im a car nut). OIL has for awhile has improved massively in the last 20+ years, take a quart of Oil from 1980 and today out in winter and pour them, simply amazing the difference, not to mention heat, which was what caused sludge in old oils, new ones can handle much more heat. And now there are detergents that help with the already mentioned moisture issues you can get with short and winter driving. Oil is just really good right now, and include the much better manufacturing abilities of the car makers, and the actual tech which has improved. So with all that, the 10,000 miles between changes, or annual changes do look pretty sound and low risk.
BUT this part gets to opinion, when I can change oil every 2,000 or 3,000 for $30 bucks (I do it myself, I vary depending on weather, drive length etc..) sure that's $60 bucks more a year for car maintenance (for oil changes), but in the end for the peace of mind, $60 more is fine with me.. (amazon has mobil one on sale for $22 often and Walmart does too). While I dont keep many cars long (car nut) i have a few that have inched up to high miles (150,000 or more, when i was younger had a couple 3800 GM v-6's with 300,000) all have lasted and all have had oil changed every 3,000 or less. I cant tell you they would not have went just as long with 10,000 between changes, they may have.
The oil companies warranty this stuff, but the fine print is it has to be from day one, and all service records are at a certified dealership for their oil, lots of loopholes and fine print.. but they do stand behind those suggested miles so you should be OK.. again it gets down to how much you feel your car is worth. I live in town so there is so much short driving and I live in ND so the weather is all temps. It was close to 100 the other day, then we had 65 for a high a day later.. Im changing far sooner than suggested.

its the same with auto tranny fluid, for awhile everybody suggested 30,000 changes, then in the late 90's many went to 100,000 (some cars came with NO DIPSTICK to even check them) I have a Chrysler Crossfire (Mercedes SLK basically) it has no way to check, you take to a dealer and pay $60 for a part (it breaks when its checked, interesting design) and $100 labor.. Its supposed to be good for 80,000 (dealer check) then LIFETIME! dont need to check again.... My point this stuff is covered by dealer , these long length between changes so it must be ok, but keep in mind most warranties are not much more then 30,000 or 60,000, not long term.

Ok after that monstrous novel.. its up to you, I know somebody can discount any of my points , i just feel piece of mind is a few more oil changes.

OP that low of miles, i have to say once a year would be fine, I have a convertible that gets maybe 600 miles a year, I have let it go 2 years (its in heated garage, never outside except summer ) but normally change it once a year.

 

[WackyDan]

You don't need to use synthetic if you are driving that little and changing once a year.

 

[lxskllr]

You don't need to use synthetic if you are driving that little and changing once a year.

I use walmart synthetic. It costs a couple bucks more than standard for a five quart bottle. No real reason not to for that price difference. I change my oil twice a year, and drive 25k/year. I get >200k miles out of my vehicles. Would I get more with more frequent changes? Maybe, but after 200k you're going on luck imo. Anything could happen at that point, regardless of the care you gave the car.

 

[VirtualLarry]

Interesting subject.

I've got a 2004 Oddessy, and I generally get my oil changes at the dealer. Last oil change, the sticker says 02/2016. Little past that now... Anyways, I have yet to hit the mileage mentioned on the sticker, but I'm getting close.

When I get some money, I'll bring it in. Should have been this month, but I bought a Ryzen CPU + mobo, and ten XBOne controllers. (Ok, went a little overboard on the controllers.)

 

[Muse]

You don't need to use synthetic if you are driving that little and changing once a year.

Yeah, but synthetic is pretty cheap at Costco on sale or Walmart. I've seen it touted for being better for going longer between changes, that's why I use it. I have at least 2 more changes worth on hand, Mobil 1 full synthetic.

My mechanic (used to be, haven't seen him in 6 years or more, I think) told me that if it was his car and he didn't drive it all that much (sat for 2+ weeks at a time not infrequently), he'd make an effort to make sure the gas tank was pretty full. That way there's less of an issue of water condensing into the fuel. I try to keep the tank pretty full. These days I drive to Costco every two weeks (used to be every 2 months), a 5 mile drive each way (sometimes I intentionally stretch that to give the car the bi-weekly workout people recommend) and if the gas gauge shows 25% empty or so I fill up if the lines aren't too long or a gas truck isn't pumping gas into the tanks stirring up the sediment and sludge.

 

[dave_the_nerd]

Interesting subject.

I've got a 2004 Oddessy, and I generally get my oil changes at the dealer. Last oil change, the sticker says 02/2016. Little past that now... Anyways, I have yet to hit the mileage mentioned on the sticker, but I'm getting close.

When I get some money, I'll bring it in. Should have been this month, but I bought a Ryzen CPU + mobo, and ten XBOne controllers. (Ok, went a little overboard on the controllers.)

This post makes me cry.

 

[madoka]

I would still change the oil annually. Short trips won't evaporate the condensation that builds up in the engine and is carried off by the oil.

Do you make sure to get the oil all over the engine?

 

[Carson Dyle]

Just keep changing it annually. Hell, you're only talking about $30-40 a year, even using synthetic.

 

[jlee]

Do you make sure to get the oil all over the engine?

What?

 

[bruceb]

I use Mobil 1 Full Synthetic in my Grand Prix and it gets changed around every 6K miles. My 216 Cadillac ATS 3.6 engine probably came with Mobil 1 from GM and for it's first oil change it will be around the 1,000 mile area. Right now the oil life monitor says 20% life, but a lot of the trips with it are about 25 or 30 miles, around town 30 - 45 MPH and some highway speeds 55 - 70 MPH ... That car will also get Mobil 1, maybe the new extended life version, full synthetic as it will meet the GM DEXOS 1 Oil Spec that GM wants for the oil. For now, I will be using the GM PF63E oil filter. Later on, I may try the Mobil 1 Oil Filter .. prices are similar for both & Walmart carries both brands. And I just got my rebate of $15 from Mobil 1 from their last buy Oil & Filter offer about 2 months ago.

 

[bigboxes]

Since Walmart is carrying Mobil 1 for fairly cheap, I have been going that route. When I first started using synthetic, I was just using regular Fram filters and changing it every 5K. But I've been using a qualilty Wix filter that is rated very high and for higher mileage that I just change the oil at 10K these days. If I go over 10K I don't sweat it, because I know the filter and the oil can handle it.

 

[bruceb]

Yes, the Mobil 1 Full Synthetic at Walmart is about $29.99 for the 5 quart jug and can sometimes be had for around $22 .. individual quarts run about $5 to $6 each. If you go for the extended life Mobil 1, you can expect to pay around $50 or so for the 5 quart jug. Now my Cadillac takes 6.5 quarts with the filter change (3.6 engine with AWD) non AWD with same engine only takes 6.0 quarts

 

[Meghan54]

At my local WM, regular Mobil 1 is $22.47, as are the M1 High Mileage and AFE variants. Mobil 1 Extended Performance is $25.42. Mobil 1 Annual Protection recently dropped in price to $39.84. All normal, everyday prices. No coupons, rebates, etc. Have used some M1 variant many times over the years. Works as well as anything else. (Prices are for 5 qt. jugs.)

Ran a change on Castrol Magnetec synthetic, did well, and currently have M1 AFE 0W-30 in my truck...although it's down 1/3 of a qt. now (after ~2k miles), a change that wasn't happening before. Truck never burned any oil before the AFE. Meh....next oil change, Castrol Edge Extended Performance probably will go in.

Have found the Fram XG filters to be excellent and rated to hold more dirt than any Wix filter. But wouldn't use any other Fram filter, tho. AC Delco filters are reputed to be quite good, too.

My oil change interval averages out to around 7k miles. Use the OLM and change at roughly 10% life. Has consistently been around 7k miles for that.

Yes, the Mobil 1 Full Synthetic at Walmart is about $29.99 for the 5 quart jug and can sometimes be had for around $22 .. individual quarts run about $5 to $6 each. If you go for the extended life Mobil 1, you can expect to pay around $50 or so for the 5 quart jug. Now my Cadillac takes 6.5 quarts with the filter change (3.6 engine with AWD) non AWD with same engine only takes 6.0 quarts

 

[JCH13]

If you want to know for sure, get a used oil analysis (UOA). Then you can make a decision based on empirical data and a professional recommendation.

 

[Carson Dyle]

If you want to know for sure, get a used oil analysis (UOA). Then you can make a decision based on empirical data and a professional recommendation.

If you're driving 15 or 20 or 30,000 miles a year, that makes sense. And only if the goal is to save some money, so that you can run to 10 or 12,000 or more miles between oil changes instead of simply changing it more often.

But if you're driving under 5000 miles a year, it would be foolish, and saves you _very_ little money to change it less often than once a year. Even twice a year isn't be a bad bit of insurance for an extra 30 or 40 bucks.

 

[JCH13]

If you're driving 15 or 20 or 30,000 miles a year, that makes sense. And only if the goal is to save some money, so that you can run to 10 or 12,000 or more miles between oil changes instead of simply changing it more often.

But if you're driving under 5000 miles a year, it would be foolish, and saves you _very_ little money to change it less often than once a year. Even twice a year isn't be a bad bit of insurance for an extra 30 or 40 bucks.

I don't disagree that the costs involved are low. However, that's not what OP was asking about. They asked when they should be changing their oil, and a UOA is the right way to definitely answer that question.

Also, a UOA only costs $28, and the test kit is free. If it saves one synthetic oil change in the life of the vehicle, it was worth it.

 

[Carson Dyle]

I don't disagree that the costs involved are low. However, that's not what OP was asking about. They asked when they should be changing their oil, and a UOA is the right way to definitely answer that question.

Also, a UOA only costs $28, and the test kit is free. If it saves one synthetic oil change in the life of the vehicle, it was worth it.

Did you miss the part where the OP said he's only driving the car about 1500 miles per year? So he gets an oil test and it recommends he change the oil every 10,000 miles... And then what?

 

[JCH13]

Did you miss the part where the OP said he's only driving the car about 1500 miles per year? So he gets an oil test and it recommends he change the oil every 10,000 miles... And then what?

If the Blackstone Lab experts suggest an extended OCI then OP has professional buy-in to do so. That's worth a hell of a lot more than a bunch of opinions and speculation from people on the internet. They could even test once a year to monitor the time-based degradation/oxidation of the oil, moisture uptake, etc. It addresses all of the speculative concerns brought up in this thread for less than the cost of a tank of gas.

Like I said, quantitative testing is the only way to definitively answer OP's question: 'should I be changing my oil/filter less frequently than once a year?' What OP considers actionable after learning the test results in up to them.

 

[Carson Dyle]

Oh, dear God. Talk about overthinking something to the nth degree.

 

[blankslate]

Oddly enough full synthetic oil might not be made from a pure synthetic base.

Granted this youtube user also is a seller a particular brand of oil but perusing some forums seems to back up what is stated in the video about the base stock used in to make the oil Group III vs. Group IV.
https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=950311

Full Synthetic is still better than nonsynthetic or synthetic blend oils imo.

But until I get an oil analysis done on my used oil I've been changing my oil before my the oil life monitor goes below 30% in my car using full Synthetic and a filter rated for 10k miles. Usually it's changed at about 5k miles maybe 6k which happens to be before the intervals suggested under severe usage in my manual.

Interestingly enough I read that about 60% of drivers on average tend to fall into the severe use category because they tend to drive less than 10 miles per trip in stop and go traffic and not very often at highway speeds on freeways for 20-30 miles. From what I've read driving at highway speeds for a reasonable amount of time tends to evaporate moisture that can gather in the oil better than shorter trips with a lot of stop and go cycles at traffic lights.


___________

 

[RLGL]

Also, a UOA only costs $28, and the test kit is free. If it saves one synthetic oil change in the life of the vehicle, it was worth it.

What a waste of money, I can do a Mobil 1 oil and filter change for that.