Why is 5k the standard for conventional?

[FCD]

My daily driver Peugeot 106 gets nothing but parts store brand 10w40 semi synthetic, i haven't changed the oil in the 2 years i've had it just the filter a year ago or so, it burns some oil so i have to top it up every now and then. I might change it soon though i don't want the engine to sludge up and sieze as i'm driving to work shich would force me to use my Capri that gets 20mpg on a good day....

 

[circuitsmith]

Originally Posted By: SR5
So true. I work with scientists, engineers and machinists. All are well educated and drive cars, some are interested in oil, however most are not.


Same at my (university) job.
One day I'm walking through the parking lot. Notice one of the engineering professors driving in in a Corolla.
All four tires look flattish. I mention this to him.
He gets testy, saying he uses a good mechanic who checks out everything when he takes it in for service.
"How long ago was it last checked out?", "Oh, about 9 months"
A few days later he passes me in the hall and says he had the tires checked and they had about 18psi.

 

[Garak]

Or, the petroleum engineer that asks me where to buy oil.

Well, he's a petroleum engineer, not a lubricant engineer or a formulator. He finds the stuff for the oil companies; he's not in distribution.

 

[Boss302fan]

Originally Posted By: doublebase
Originally Posted By: HTSS_TR
My 1994 Lexus LS400 recommended 7.5k for dino 5W30. 5k wasn't the standard for conventional oil ever, some manufactures may recommend 5k but not all.


What? Where does it say that in the owner's manual? I own a LS460 and the recommended oil changing interval is 5,000 miles.


I have a 2006 LS 430 and the normal OCI is 7500 miles on syn or convention oil. I use a syn oil and usually do one year OCI's up to 7500 miles. I have drained syn oils at 5K because I was overly anxious to do the oil change. LOL.

Your car should also be 7500 miles unless your dealer just wants to get you in at 5K and then sell you other services... My mother has a 2006 GS430 and she bought it new and has gotten free oil changes every 6 months from the dealer since her purchase from Lexus of Naples. LOL. She has around 30K on the car and has done a few changes with only 1K on the OCI.

 

[addyguy]

5k change intervals have been around for a long time. A 1976 AMC called for oil changes every 5k or 6 months. Ford has called for 6k changes since the 1960's. My 2010 Soul calls for 5k or 4 months.

The quick-change industry 'reinforced' the idea that 3k changes were necessary, but with oils getting better, todays '3k' is 5k for cars that don't have some form of OLM.

 

[TiredTrucker]

I like the 5K thing. My pckup does a lot of gravel road, farmland kind of operation. I get under the pickup every 5K to inspect and grease. Convenient to just drop the oil and change filter while I am there.

 

[BAJA_05]

I personally think it all pertains to a persons driving habits. If your only short tripped and rarely or never get on the highway/freeway at all like some people I know who live in a small rural town that I live in. Three thousand to four thousand mile OCIs are not irrelevant on conventional. Especially after a good cold winter.

 

[BAJA_05]

I personally think it all pertains to a persons driving habits. If your only short tripped and rarely or never get on the highway/freeway at all like some people I know who live in a small rural town that I live in. Three thousand to four thousand mile OCIs are not irrelevant on conventional. Especially after a good cold winter.