Oil changes maintenance Schedule
Instructor
Joined: Feb 2021
Posts: 835
Likes: 408
From: PA
I completely understand that fresh motor oil and oil changes are cheap insurance and are absolutely crucial to the life of an engine. I also know that multiple short trips are very bad for an engine since some of the moisture generated by combustion condenses in the oil, and if the engine has not warmed up fully to boil off this water, then the result will be increased engine corrosion. For this reason, Lexus says to change your oil every 10K miles or 12 months, whichever comes first. Makes perfect sense for those cars driven the usual 10-15K miles per year.
One of my cars was bought new in 2020 and because of COVID-19, and because we tend to use our other car much more frequently, this car has only been driven about 5,000 miles (it’s on a Battery Tender until we need it). But, importantly, I know that when we do take it out, that we drive 20 or more miles until the oil is completely warmed up. I’ve long known from my Vette which had an oil temperature gauge, that the oil takes far more time to get to temperature than the coolant.
So, my argument is that, ignoring warranty concerns, that waiting a bit longer than 12 months does not do the engine any harm under these driving conditions. I am certainly not suggesting delaying the oil change until 10K, but it seems to me that changing say every 24 months or so under these circumstances would not harm the engine.
Interested in everyone’s thought on the subject.
One of my cars was bought new in 2020 and because of COVID-19, and because we tend to use our other car much more frequently, this car has only been driven about 5,000 miles (it’s on a Battery Tender until we need it). But, importantly, I know that when we do take it out, that we drive 20 or more miles until the oil is completely warmed up. I’ve long known from my Vette which had an oil temperature gauge, that the oil takes far more time to get to temperature than the coolant.
So, my argument is that, ignoring warranty concerns, that waiting a bit longer than 12 months does not do the engine any harm under these driving conditions. I am certainly not suggesting delaying the oil change until 10K, but it seems to me that changing say every 24 months or so under these circumstances would not harm the engine.
Interested in everyone’s thought on the subject.
https://www.blackstone-labs.com/
Pit Crew
Joined: Feb 2021
Posts: 143
Likes: 138
From: Pennsylvania
Oil change interval -- ??
I have a 2021 Lexus RX350 that I purchase back in 2021 I had my oil changed at the Lexus dealer and they put a window sticker for the next oil change to be done in 5,000 miles. I ended up going to the local Toyota dealer as closer to my house and had the oil changed and they put a sticker for the next oil change to be at 10,000 miles. So I guess my question is what is everyone doing for their oil change interval? I thought I did read at one point that it is every 10,000 miles and to be honest I did think it was a little strange that the Lexus dealer put 5k for the next one.
Racer
Joined: Nov 2017
Posts: 1,941
Likes: 581
From: New York
I have a 2021 Lexus RX350 that I purchase back in 2021 I had my oil changed at the Lexus dealer and they put a window sticker for the next oil change to be done in 5,000 miles. I ended up going to the local Toyota dealer as closer to my house and had the oil changed and they put a sticker for the next oil change to be at 10,000 miles. So I guess my question is what is everyone doing for their oil change interval? I thought I did read at one point that it is every 10,000 miles and to be honest I did think it was a little strange that the Lexus dealer put 5k for the next one.
Racer
Joined: Apr 2016
Posts: 1,387
Likes: 349
From: ON
I have a 2021 Lexus RX350 that I purchase back in 2021 I had my oil changed at the Lexus dealer and they put a window sticker for the next oil change to be done in 5,000 miles. I ended up going to the local Toyota dealer as closer to my house and had the oil changed and they put a sticker for the next oil change to be at 10,000 miles. So I guess my question is what is everyone doing for their oil change interval? I thought I did read at one point that it is every 10,000 miles and to be honest I did think it was a little strange that the Lexus dealer put 5k for the next one.
Or maybe Ravenuer is right...it's all about the money!
Last edited by FastFord; Sep 25, 2023 at 01:03 PM.
Racer
Joined: Nov 2017
Posts: 1,941
Likes: 581
From: New York
Advanced
Joined: Aug 2006
Posts: 645
Likes: 135
From: NJ
To take it a step further, at the end of 24 months and just before you change your oil, send in a sample to Blackstone Laboratories in Ft. Wayne, Indiana for analysis. You might gain some valuable info about your engine. It doesn't cost that much and you can order a free test kit right here:
https://www.blackstone-labs.com/
https://www.blackstone-labs.com/
Intermediate
Joined: Dec 2021
Posts: 264
Likes: 101
From: Surrey
Good idea. Anyone know of an easy way to remove a small oil sample from the engine without having to completely drain the oil from the oil pan? I know there are various apparatus for sucking up the oil through the oil dipstick tube but wondering if there are more simpler sampling devices.
If it's of any interest, prior to me buying it, it transipred that my car missed a couple of oil changes during covid. Mileage between the last two changes seemed to be about 30k. I was somewhat annoyed at the supplying dealer not noticing this, as it wasn't easily apparent from the service records/receipts. Anyway, I got the old oil tested, as well as samples at the next two oil changes, and they all came back fine, and the car's still running like new.
I get why people get all caught up in 5k/6 month oil changes, especially if it's inexpensive, but there are probably worse things you can do in terms of maintenance than just sticking to the 10k/annual manufacturer recommendation.
Instructor
Joined: Sep 2015
Posts: 979
Likes: 696
From: Ohio
Good idea. Anyone know of an easy way to remove a small oil sample from the engine without having to completely drain the oil from the oil pan? I know there are various apparatus for sucking up the oil through the oil dipstick tube but wondering if there are more simpler sampling devices.
To answer your question, yes, if you will remove the oil filter cover and carefully remove the filter itself, then with a syringe you could remove a sample of oil, and put the filter back in. This is NOT a recommended way to get a sample, however. When changing oil from a warmed-up engine, removed the drain plug and let the flow begin, then use a container like a clean tin can, clean plastic bottle with the top cut off, etc. to catch a few ounces of the oil in mid-drain. That's your best sample -- not the first oil out, not the last oil out, but the oil in the middle of the drain.
Blackstone labs will provide you a nice report, with analysis, via email if you provide that information with your sample.
Advanced
Joined: Aug 2006
Posts: 645
Likes: 135
From: NJ
You really, really, really should change it after that long, regardless of mileage. You can find an expert mechanic on the Car Care Nut's youtube channel who recommends changing every 5K miles or 6 months, whichever comes first, and he's a Toyota/Lexus expert mechanic.
To answer your question, yes, if you will remove the oil filter cover and carefully remove the filter itself, then with a syringe you could remove a sample of oil, and put the filter back in. This is NOT a recommended way to get a sample, however. When changing oil from a warmed-up engine, removed the drain plug and let the flow begin, then use a container like a clean tin can, clean plastic bottle with the top cut off, etc. to catch a few ounces of the oil in mid-drain. That's your best sample -- not the first oil out, not the last oil out, but the oil in the middle of the drain.
Blackstone labs will provide you a nice report, with analysis, via email if you provide that information with your sample.
To answer your question, yes, if you will remove the oil filter cover and carefully remove the filter itself, then with a syringe you could remove a sample of oil, and put the filter back in. This is NOT a recommended way to get a sample, however. When changing oil from a warmed-up engine, removed the drain plug and let the flow begin, then use a container like a clean tin can, clean plastic bottle with the top cut off, etc. to catch a few ounces of the oil in mid-drain. That's your best sample -- not the first oil out, not the last oil out, but the oil in the middle of the drain.
Blackstone labs will provide you a nice report, with analysis, via email if you provide that information with your sample.
Instructor
Joined: Dec 2002
Posts: 1,043
Likes: 31
From: CA
Thanks for you input. I know you know that it is not surprising that Lexus/Toyota mechanics recommends 5K/6 mo. oil changes. They would recommend 500 mi/6 week oil changes if they thought we would believe them. My particular situation where the car is very rarely driven, and when it is driven, it is driven until it is fully warmed up, is analogous to having a car with fresh oil sitting without being driven at all. I don't think any of us would change the oil every 12 months. I maintain, that it is unnecessary to drain and refill my oil after only 12 months of my extremely light use. I understand the oil change mantra (and will not wait until 24 months to change my oil), but I'd like someone to explain to me technically why nearly clean oil should still be changed every year.
The main idea is because motor oil is not in a sealed system, so it's exposed to combustion gases including water vapor. It never "clean" anymore once it enters service. All the additives in the oil go to work and don't pause just because the car is off. So the one year is a time based limit.
The analogy is like opening food. Clock starts ticking once you open a jar or can or bag and your chips going to go stale whether you eat them or not.
Last edited by raytseng; Oct 1, 2023 at 04:00 PM.
Advanced
Joined: Aug 2006
Posts: 645
Likes: 135
From: NJ
I don't think there are any truly, technically, 100% synthetic oils out there. From what I understand, the base stocks of all current "100%" synthetic oils are ultimately derived from petroleum. Goes back to that old Mobil 1 vs. Castrol litigation.