Just curious, have you used one these dealer offers? I get then too but I have always found some fine print where it says something to the effect that it does not apply to synthetic oil and usually a number of other conditions.
I do my own so I know it is done right.
I canāt see you going far wrong w/5K oil and filter changes, esp when using synthetic. Good for you for keeping on top if it. Rather than focusing on the exact number of miles, make sure to use a well known name brand oil hosting the specs Toyota requires for that engine, and a quality oil filter. Itās best to stick with the same brand of oil once you choose one, rather than switching brands change to change. If you want to go the extra mile, rather than aftermarket oil filters, use oem oil filters you buy from a Toyota dealership.
Iāve always wondered about that sticking with the same brand theory. Before I heard of that theory, I put 200k miles on a Dode truck switching oil brands, buying whatever was the cheapest name brand oil at the time. I sold the truck, never had any engine issues. I did replace the intake manifold gasket at around 180k miles. The inside of the engine (that I could see) looked very clean - no sludge buildup or anything.
I think Iāve decided that if you had to be oil brand loyal, oil companies would periodically give away free oil to get you hooked on their stuff. But I could be wrong.
I heard that from a pro mechanic who has owned his own shop for years. His explanation is that while all the major brandās oils are excellent, each uses slightly different formulations for their additives. And those additives may or may not be compatible. So in his opinion best not to take that chance of an additive incompatibility resulting in an expensive repair. As you might expect, not everyone here agrees ā¦ lol ā¦
The only time Iāve let anyone else change my oil is when it was free. The first oil change on a certified used car we bought my wife in 2008 was free. When she got home, I could tell the hood was sitting kind of cockeyed. Theyād left the oil cap on the cowl and closed the hood on it. Sheād driven it 30 miles home like that. The oil level was fine, so I replaced the cap and bent the edge of the hood back by hand. No harm was done, but I did mention it when GM service called me to inquire on my satisfaction with my latest visit. They offered me a free oil change for my trouble! I declined, but said Iād take some free oil and a filter and change it myself. And they declined that. Oh well. Was worth a shot.
I have to say, the dealer can change the oil for only a few bucks more than I can do it myself since they buy bulk oil. But changing it myself gives me a chance to crawl under the vehicle and give it a look under the hood for anything else that might need attention. Of course, you can let someone else change your oil and do the same inspection, but if Iām being honest, I probably wouldnāt.
My Toyota dealer gets $60 for a synthetic oil change. If you are getting $20 offers, they are for conventional oil that is not supposed to be used in your car except in an emergency. The closest quick lube place to me gets $75.
I change my own, I drive 7000 miles a year since I retired so I change it every August. Costs about $30 and while I am waiting for the oil to drain I check out the underside looking for leaks, torn CV boots and pull a front and back wheel to check the brakes.
No worries. Iāve heard theories that it was more of a problem in years past. But I donāt personally know. Nothing wrong with finding a brand you like and sticking with it anyway. My dad was a Havoline oil and Fram filter man. I suspect that was because Wal Mart sold those brands cheaper back in the day. I used Fram oil filters exclusively on that Dodge for 200k. Then I heard they were garbage per the Internet. Who knows.
Speaking of cheap filters, I used a Microguard cabin air filter on the Highlander this time. I figure itās a cabin air filter, whatās the worst that can happen if itās no good? It looked like a better quality filter than the Wix it replaced. I was surprised.
Toyota also charges me 60 dollars for just oil change and with tax, around maybe 67 dollars
And does he also say to not put regular plain old air in a tire that has nitrogen in it.
Extended interval is NOT the benefit.
. Less likely to sludge due to itās ability to handle high heat better. Some engines are prone to sludge. Toyotaās 3.0L was one.
. Old weather starting. Synthetic oil will flow well even at temps well below zero.
Stick with the recommended oil weight. The engineers who designed the engine know a lot more about what oil to use then you do. 0w-20 is the recommended oil for my '14 highlander. Now have over 80k miles and runs great. I change it every 5k. But I tend to keep my vehicles over 300k miles,
0w-20 is synthetic or synthetic blend ONLY.
With coupons they offer quite often, itās cheaper for me to get my wifeās car (2012 Chevy Malibu) oil changed at the dealership than it is to do it myself. Plus they toss in a car wash and a tire rotation that I donāt have to do. 
I do have to listen to the sales pitch of the upsell, but I know enough about the car to know what it needs.
Yes, less likely to sludge. In an extended drain interval. Iāve never had an oil sludge problem on non synthetic changing every 5k. We donāt get a lot of below zero temps in Mississippi, so not too worried there either.
The manual states 5w20 is ok, but to replace with 0w20 at the next oil change (5k miles later). So I assume if itās good for one 5k mile interval, itās good for several 5k mile intervals.
The manual also states to change every 10k on synthetic, so youāre not following it to a T either. The manual states the trans is sealed for life as well. But I plan on changing the fluid.
Iām pretty sure the switch from 5w20 was done to increase fuel mileage. Toyota changed from recommending 5w20 to 0w20 across all models at some point a few years ago.
Iām not arguing that others should do what I do. But Iāve never seen any true data showing 5w20 isnāt acceptable. And again, do not see a benefit to synthetic oil if youāre not extending the drain interval to the mileage the manual states (10k). Near 90k miles now. Iāll report back at 200k 
I know of no studies that would support the āstick with one brandā advice. As long as itās the right grade and type, switch at will.
Toyota owners with the 3.0l engine did. Thousands of them did.
Never knew a Toyota vehicle that the recommended oil was 5w-20. 5w-30 - YESā¦but not 5w-20.
My 05 4runner was 5w-30. Wifes 07 Lexus with same engine as my Highlander is also 5w-30.
What Toyota engines/years recommended 5w-20?
Try living in North Dakota some winter and tell me again. I have relatives in NY who live by the Canadian border. Before synthetic oil - on real cold nights (-20 or lower), they would either get a block heater, or drain the oil every night and bring it insideā¦Then refill engine with the warm oil.
https://www.vehiclemd.com/synthetic-oil-protecting-your-engine-in-extreme-temperatures/
If you do a lot of hauling (towing a camper)ā¦puts a lot more stress on the engine that can greatly benefit from synthetic oil.
Oh man, thatās funny!
I lived 40 years in an area that saw -25 at night with highs of -10 in the day for several weeks straight. Nobody did anything different let alone taking their oil inside at night. And we were running 10W30 back thenā¦
My Aunt who lived in Massena NY died some 40 years ago. We went up there for 3 days for wake and funeral and to help cousins with the house. Two nights it was -45. Conventional oil is like a paste at that temp.
Iāll give you that. Although you said -20 or lower above, -45 is significantly lower. Still, I would use a block heater before taking the oil in for a heated napā¦
Yeaā¦I knowā¦but they get -20 a LOT. Iāve only seen -20 twice my whole life where I live. They see it 10-30 times a year. This was very common back in the 60ās and 70ās. One reason all my cousins owned full size pickups. Just slide under the truck. My two cousins at the time lived in an apartment and couldnāt use block heaters. They swear their engines lasted a lot longer then others who lived in the are and didnāt do this or use a block heater.
Lol, ok. 5w30. They recommended 5w30 for a Lexus with the same engine that theyāre now recommending 0w20ā¦in your words. So you sort of made my pointā¦
If I wanted to try anything in North Dakota, Iād move there or watch āFargoā again, right?
I donāt tow or haul anything with a V6 Suv.
Listen, I agree, synthetic is better. I just donāt feel comfortable with a 10k mile interval on any oil. Using synthetic is wasted money on a 5k mile interval in my opinion, and in my conditions. And they donāt make an 0w20 other than synthetic.
Fact of the matter is, according to what you say, I should be able to use 5w30.
I do hate when people sayāfollow the manualā, then they pick and choose which parts of the manual they follow. If you follow the manual, youāll change it at 10k, unless youāre towing a travel trailer with a V6 or using that higlander as a taxi.
Iām going to edit this, Mr. Mike. I came off a little harsh. I donāt want to argue. I have no proof, and I donāt think you do either. I bought my wifeās Highlander new. Paid cash for it. I did research before coming to the conclusion that 5w20 was safe. But I do not have definitive proof. The only proof Iāll have is if the car makes 200+K miles. If it doesnāt, Iām wrong. I personally donāt want to drive it to 300k with all the other components that will wear out. Personal preference.