Oil Change Interval

treillw

WKR
Joined
Mar 31, 2017
Messages
1,967
Location
MT
How do the oil life indicators on vehicles work? Is there some science behind it, or is it just arbitrary?

If I didn't use the life indicator, I would be changing oil a lot more frequently (every 5000 miles).

Makes me wonder if I should trust the computer.

Thanks!
 

Beendare

WKR
Joined
May 6, 2014
Messages
8,511
Location
Corripe cervisiam
I use synthetic…and do 7,000 but check it periodically and if it looks bad change it more often.

I had a Brit buddy that had a theory that it was better never to change your oil. He was bragging about his little compact Mercedes that went something like 80,000 miles without an oil change- then no shocker…. He blew up the motor.
 

Tjdeerslayer37

Lil-Rokslider
Joined
Jul 10, 2020
Messages
166
Location
Wayne, MI
the vast majority of the computers are just a preprogrammed mileage timer. im not aware of any that actively monitor the life in a way that conveys the oil's actual ability to cool and lubricate. the only true way to know if youre going too long or changing too early is by getting a used oil analysis done. most people arent going to go to those lengths so the next best is to follow the service schedule in the manual.

if you really want to nerd out, visit https://bobistheoilguy.com/forums/ sometime.


edit: Dealerships have been known to change the computer timer to shorter intervals to make themselves more money by doing more services, thats why i suggest falling back on the service schedule in the manual.
 
Joined
Dec 31, 2021
Messages
1,738
Location
Montana
I change my diesel truck every 5000 miles. The book says every 7000. The math is just easier.

A number of discussions I had with chem. engineers over the years, said the oil is stable but the additives have a shorter life span by time and miles. Oil is cheaper than an engine.
 

dtrkyman

WKR
Joined
Oct 2, 2014
Messages
3,028
I have a 2013 Grand Cherokee(v6), bought it new and have 199,400 miles on her. Change the oil when it tells me, seems to be around 7k, though I do remember one time it went to 10k before it came on.

Always full synthetic.
 
Joined
Nov 30, 2020
Messages
343
I change mine earlier than the indicator says and it is always looks like it needed it. As stated above, an oil change is a lot cheaper than having something happen with the engine. Walmart is the best price for Mobil -1, just have to deal with Walmart things while in there….
 

CorbLand

WKR
Joined
Mar 16, 2016
Messages
7,208
I change mine earlier than the indicator says and it is always looks like it needed it. As stated above, an oil change is a lot cheaper than having something happen with the engine. Walmart is the best price for Mobil -1, just have to deal with Walmart things while in there….
Also watch Mobil 1 website for rebates. They have ran some really good ones in the past.

I set the service interval on the wifes car for 5000 and change when I have time and its getting close. Sometimes its a couple hundred miles under, sometimes a couple hundred over.

It cost about 40 bucks to change the oil and I do it about 4 times a year. Way cheaper than a new motor.

I have had really good luck with NAPA branded oil too. You can get some good deals on it sometimes.
 

dtrkyman

WKR
Joined
Oct 2, 2014
Messages
3,028
I have proably used a dozen different oils in that grand cherokee over 200k, how would one know they had good luck with oil?

A straight up blown engine seems un common these days.
 
Joined
Aug 26, 2013
Messages
2,294
Location
New Orleans, La.
I use Amsoil Signature Series synthetics in my personal vehicles. The oil is good for 25,000 miles, just change the filter at 12,500 and top off and you're good for another 12,500. I personally change it about every 10,000, or once a year (which is overkill for Amsoil Signature). A quality oil filter is key also. NAPA Platinum (designed for synthetic oil), or Amsoil 15k series oil filters are top rated.
 
Last edited:
Joined
Sep 24, 2019
Messages
972
I was changing mine according to the DIC. I sent my used oil in for analysis a couple of times to get a baseline. I use traditional Mobil Delvac cheap oil and after 5k and 7k, the viscosity was still in the threshold. That being said, synthetic oil was unnecessary. I still change at 5k. Engine is a Duramax l5p gen 1.
 

CorbLand

WKR
Joined
Mar 16, 2016
Messages
7,208
I have proably used a dozen different oils in that grand cherokee over 200k, how would one know they had good luck with oil?

A straight up blown engine seems un common these days.
I have used it for about 35,000 miles (~6 oil changes) and have had zero issues caused by it. It came recommended by a friends dad who has used it in all their vehicals for the last 5 plus years with zero issues.

I would say that I have had good luck with it in the sense that when it goes on sale, you can get it for about 4 bucks a quart, which is cheaper than I have seen anything else in the last couple years and it has caused zero problems.
 

dtrkyman

WKR
Joined
Oct 2, 2014
Messages
3,028
I used Mobil one for a while when I had a Costco close by, good pricing. But I would use anything synthetic personally, most of my oil changes were done by a shop anyway.
 

CorbLand

WKR
Joined
Mar 16, 2016
Messages
7,208
I used Mobil one for a while when I had a Costco close by, good pricing. But I would use anything synthetic personally, most of my oil changes were done by a shop anyway.
I have also used Mobil one and other different synthetics. Use what you want, I am not here to tell you not to nor did I tell anyone they should/shouldnt use anything.

I just stated that I have had good luck using NAPA branded oil.
 
Joined
Nov 12, 2020
Messages
1,236
I would read up how the manual states the recommendation for oil changes. Usually it’s best case scenario and most of us don’t drive that way. Basically if all your miles are highway miles you could probably stretch it out to 10k miles. But if you’re in stop and go traffic or short runs your oil isn’t gonna hold up as well. The only way to truly know if have an analysis done.
 

flyfisher117

Lil-Rokslider
Joined
Apr 2, 2013
Messages
271
Location
Idaho
I don't know of a passenger vehicle that us actively monitoring oil. Seems to be mostly a generic mile meter, though I had heard some monitor mileage and operating hours and calculate it based off that. No proof though.

I just change mine every 5k. Easy to track and ends up being 2-3 oil changes a year. Used to pay the stealership thr money but after they stripped my skid pan bolts and left the skid pan hanging I decided I'll take the time and do it myself. End up saving money to boot.
 

ODB

WKR
Joined
Mar 24, 2016
Messages
3,865
Location
N.F.D.
5k on all my Toyotas.

I did go almost 10k on my 02 Tundra once and I’ll never do that again. That oil was ugly.
 
Top