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Oil life

So, I recently got a new Kia Sporage (2.4L 4 cycle engine). I currently have 3k miles, and plan on doing an oil change at 7,500 miles (when Kia recommends the first oil change). I am still finding it hard to believe that the engine can go that long with conventional oil, but I am just following the manufacture recommendation. I do mostly highway driving (no real stop and go).

Anyway, I was wondering what all of your thoughts were in regards to spending the extra money for full synthetic if I can go that long between oil changes on conventional oil? I was always under the assumption that synthetic oil went 7500 miles, and conventional 3-4500ish.

Will the synethic just make sure that things are lubricated better over the same 7500 miles and keep the sludge out?

Thanks much!

Does your vehicle manual not list what fluids the manufacture recommends ?

I wouldn’t extend the oil change interval just because I switched to synthetic. If your car doesn’t require synthetic, I don’t see any need to use it. You might invalidate the warranty using synthetic if you extend the interval. As an experiment, I did switch my 1988 push type lawnmower from straight #30 heavy detergent to 10W-30 full synthetic. The mowee no longer fogs for mosquitoes while I mow(the oil consumption was dramatically reduced) so there are probably benefits to synthetic.

In one your other threads it was suggested that you talk to the dealer about what oil to use, why do you not do that? The last thing you want to do is void your new car warranty.

Syn or dino, the interval should be the same and I wouldn’t wait until 7500. My first oil change in my Acura was at 5000 with full synthetic and its been every 5000 since.

Exactly what oil is recommended in your owners manual? What grade? It may also be printed on top of the oil cap. Let us know.

Changing to synthetic does not extend the oil change interval. Save your money and use good old dino oil.

Doesn’t your new Kia Sportage require oil with the ACEA A5 spec (or API equivalent)?

ACEA A5 is designed for extended drain intervals.

Whatever spec Kia requires, I believe you’ll have no problem following your owners manual for 7500 mile intervals with the oil specification they require. Others like to change it more often.

Extending oil change intervals requires oil with more additives to keep the oil from degrading. Whether it is synthetic or mineral oil is not the important thing. I have used the manufacturers recommended change interval for more than 20 years without ill effects on my cars. If Kia recommends 7500 miles for normal service, then you should be fine doing that. Excessive heat, dusty conditions, or a lot of stop and go driving would indicate severe driving conditions, but you don’t seem to experience those.

If I was at all uncomfortable going that long, I would just change it. Oil changes are cheap, even at the dealer. I’d go 5000 tops if it were me, but you should be able to get 7500 if you do mostly highway driving. Short trips on conventional, no way I’d go that long.

Use what your manual recommends.
As regards the use of synthetic and the ability to lengthen oil changes, I recommend against it. We’ve had numerous debates on the subject and there’s a lot of hype out there about it. Don’t believe the hype.

Whether you’re using dino, synthetic, or a blend, oil becomes contaminated by blowby (all engines have some) and particulates. All types of oil are subject to this. Extending time between oil changes incurs risk, and IMHO it just ain’t worth it.

If you use the specified oil, you can go the recommended interval. But I am a little old school here in that I would do that first oil change now, then another at 7500 and then 7500 after that.

My view tends to be different. A few years ago, after one of those ad infinitum ad nauseum debates on when to change oil, I sent a sample to Blackstone at 8800 miles. It was Mobil-1 EP, and it was all okay, contamination; protection in every area. It would have been perfectly good for over 10,000 miles. It was a high mileage car, driven outside she snow zone.

Most people here make their decision on oil changes for emotional reasons, and believe their decision was total logic and science. They really have no idea how much contamination and remaining additives are doing.

But. to me, that’s okay. You need explain to no one when or why you change your oil. (EXCEPT YOU MUST COMPLY WITH MANUFACTURERS REQUIREMENTS DURING WARRANTY.)

The problem is when someone tries to convince others that his wild guess is pure science.

If you want to know when to change your oil, send a sample to Blackstone at, oh, say, 5,000 miles, then 7,500, (then ??? after the warranty is up.) I don’t mean take out a sample and wait to change it. Take the sample during oil change at that mileage. You will soon know when you should be changing it. After testing mine, I started changing that oil at around 7500 miles. (Warranty was long past.)

And, yes. you certainly can extend your oil changes with synthetic oil. To say not is a perfect example of confusing an emotional decision with science.

There are more reasons for oil testing than finding out when to change oil. Blackstone can tell you if something is going wrong or excessive wear inside the motor. Head gasket problems? The test will tell you. Bearing wear beyond the normal? it will tell you. Valve train problems? the test will tell you. Blow-by? ditto. Almost any serious problem in the motor will leave its trail in the oil tested.

Having said all that, I can see nothing really wrong with the 5,000 mile change. Sure, in a lot of cases, good oil is being wasted. But, at the same time, the odds you are ever going to harm your motor with over-extended oil are slim. For the cost of a motor, an oil change every 5,000 miles dwindles into nothingness by comparison. JUST DON’T TRY TO PRESENT IT AS SCIENCE.

Oil life is determined mostly by the ADDITIVE PACKAGE, not the type of base stock. A synthetic base stock renders the oil more resistant to extreme pressures and vey low temperature start ups.

The additives package in long life oils (extended drain interval oils) is fortified to avoid ADDITIVE DEPLETION prematurely.

A typical high quality oil is at least 25% additives. Most European specs call for these long drain oils for mostly environmental reasons; they want as little waste oil as possible. As a result, European cars often have insanely long drain intervals, like the English Vauxhall I recently rented which specified 20,000 MILES (yes!!!) between changes or once a year. If I lived there I would change every 8000 miles due to the short distances driven on any trip.

P.S. @irlandes has it right, but keep in mind that the drain interval depends on your driving style, climate, the load placed on the engine. If @irlandes towed a trailer across the Mojave desert in July, he would have a different drain interval. In industry we comply with the manufacturer’s regs until the warranty expires; then all machinery change interval is subjected to monthly or tri monthly oil sampling which helps determine the drain interval as well as non regular deterioration…

Years ago I was doing this to my Chevy Impala and changed oil very 3000 miles. I showed a wear metals count of only 60ppm and no other deterioration. EXXON at that time condemned oil with 200ppm, so I had a very wide safety margin.

Yeah sure its up to the individual which makes used car shopping a crap shoot. When I traded in my Riviera with 530,000 miles on it with the engine never been opened up, the first thing the salesman asked me was oil changes. I said I change every 3000 regardless. He slapped his leg and said I knew it. I’m not saying its science, but not all emotional either. More like based on my limited 50 years and million miles of personal experience. We learn things along the way that tends to influence our decision making. Now if oil changes were $500 instead of $40, I might be willing to sharpen the pencil a little. On the other hand, I just enjoy the work.

I have two cars with the same engine. They are direct injection engines so that is always a consideration.

Your interval is probably 7500 miles for regular use and 3750 miles for the severe schedule and chances are one way or another you qualify for the severe schedule.

I am almost on a severe use, some stop and go and some excess desert dust. I use synthetic and change it every 5K miles. It helps me keep the warranty and also balance the change intervals.

I use the Hyundai/Kia filter since I have heard they are picky about that. I bought 6 online for $30 including S&H.

The Oil Life Monitor on my CR-V calls for roughly 12,000 mile change intervals.

Yep, good luck with that one.

Auto-Owner - is this 12k on Dino oil?

Just checked in my manual. Kia recommends 7,500 miles or 6 months which ever comes first. Looks like I’ll probably be hitting the mileage first! I’ll just stick with the Dino with those intervals!