quality of oil used in change VS quanitity of oil changes?

[BlueCollarTahoe]

i saw someone say that there is a study where it says it doesnt matter what you really use for oil, it matters more how often the oil is changed. anyone got any info i can read up on this? and opinions? thoughts on concept? ive been changing mine with mobil1 every 3 months or 3k miles consistently. wonder if it changing it every 2 months with a cheaper high synthentic be the same or even better for engine wear or no difference?

 

[08HoeCD]

i saw someone say that there is a study where it says it doesnt matter what you really use for oil, it matters more how often the oil is changed. anyone got any info i can read up on this? and opinions? thoughts on concept? ive been changing mine with mobil1 every 3 months or 3k miles consistently. wonder if it changing it every 2 months with a cheaper high synthentic be the same or even better for engine wear or no difference?

Your question is an interesting one.

I had read about this concept and mentioned it in a post somewhere here within the past couple of weeks. Unfortunately, I cannot recall exactly where I read it.

My hunch is that your current oil selection and frequency of oil change probably represents the best value in terms of experiencing the smallest measurable engine wear over the longest period of vehicle ownership.

 

[iamdub]

How long an oil lasts varies from engine to engine. Some are operated in worse conditions than others. Idle and running time, ambient temperature and humidity, stress (load/RPM, etc.), quality of gasoline used, efficiency of air and oil filters, mechanical condition of engine and others are all variables that determine how quickly the oil should be replaced. The 3,000 mile thing is an age-old and obsolete rule of thumb formed way back when oils (particularly conventional) were nowhere near as advanced and robust as they are now. The worst conventional oil today is worlds better than the best of those days. The bottom line is you can't change your oil too often as long as you can afford it. The 3,000-mile rule remains as a safe minimal generalization for all engines.

My best advice when running synthetic oil is to watch it. Since synthetic oil doesn't break down, it mainly needs to be changed to get the contaminants out of the engine. Yes, it loses some components over time but that's a whole other subject, thread, forum. Watch the oil, and when it gets dark, it's dirty and should be changed. If your engine is operated in optimal conditions, you should be able to get at least 5,000 miles out of it. If sticking to a 3,000 mile OCI keeps you sane and going longer would worry you, then keep with it.

I believe you would be perfectly fine running a cheaper synthetic or even a quality conventional oil and changing it at 3,000 miles or even 2,000 if that comforts you. Personally, I'd run a top-quality synthetic and longer OCI (~5,000 miles) because it has been proven time and time again that synthetic oil protects better and for longer than conventional oil. Running a quality filter (I prefer Wix) and a 5,000-mile OCI satisfies me financially and, judging by the oil's appearance, isn't too soon (wasting) but isn't too long (it's not horribly dirty).

 

[BlueCollarTahoe]

when i do change the oil it be black as tar. not gunky its very thin just black. nothing like the clearish stuff that goes in. i ran it through a paint strainer once and ran a magnet over it nothing came up or was in the strainer except what looked like to be dirt.

 

[swathdiver]

Conventional oil is dead at about 5,000 miles generally speaking. I've been running synthetic oils since I was a kid, over thirty years now. Unless you're racing with regularlty, changing the synthetic oil every 3 months or 3,000 miles in a modern engine is unnecessary. Before I had cars with oil life monitors and those that were not raced, we set them up for every 5,000 miles on synthetic oil, mostly Mobil 1 but also used Pennzoil for a time. With the oil life monitors, there were times when we were so broke and would reset the monitor a time or two before changing the synthetic again, with no ill affects.

Still on my first oil change with my new to me Yukon, after 4,000 miles the oil life monitor is still just above 50% but I'm thinking about changing it before 5K or our next vacation.

As for me and my house, it's regular Mobil 1 for our fleet. We'll run AC Delco, Mobil 1 and K&N oil filters. Next filter will be a long one.

Don't know if I've told this here before but I once blew an oil cooler line on the way to the track. Did not know it. With each pass, the car ran faster and faster. Finally, the engine temp at the end of the fourth run was about twenty degrees higher than it should it have been. Popped the hood in the pits and saw the busted line. No oil on the dipstick. Taped up the leaky line, poured in my spare quart of oil and drove 66 miles back to my shop. Tore the engine down the next day and you know what I saw inside? NOTHING! Absolutely perfect and clean inside.

 

[iamdub]

Conventional oil is dead at about 5,000 miles generally speaking. I've been running synthetic oils since I was a kid, over thirty years now. Unless you're racing with regularlty, changing the synthetic oil every 3 months or 3,000 miles in a modern engine is unnecessary. Before I had cars with oil life monitors and those that were not raced, we set them up for every 5,000 miles on synthetic oil, mostly Mobil 1 but also used Pennzoil for a time. With the oil life monitors, there were times when we were so broke and would reset the monitor a time or two before changing the synthetic again, with no ill affects.

Still on my first oil change with my new to me Yukon, after 4,000 miles the oil life monitor is still just above 50% but I'm thinking about changing it before 5K or our next vacation.

As for me and my house, it's regular Mobil 1 for our fleet. We'll run AC Delco, Mobil 1 and K&N oil filters. Next filter will be a long one.

Don't know if I've told this here before but I once blew an oil cooler line on the way to the track. Did not know it. With each pass, the car ran faster and faster. Finally, the engine temp at the end of the fourth run was about twenty degrees higher than it should it have been. Popped the hood in the pits and saw the busted line. No oil on the dipstick. Taped up the leaky line, poured in my spare quart of oil and drove 66 miles back to my shop. Tore the engine down the next day and you know what I saw inside? NOTHING! Absolutely perfect and clean inside.

Agreed, and good story. I wonder if the engine in your racecar was getting stronger from the crank not hitting oil or maybe less oil pump drag?

I disregard that oil life monitor. If I went by it, I'd be having 15,000-mile OCIs. 5,000 is a nice, round number to do the oil and tire rotations. I could go with 6,000-mile services, but it's easy to count by fives so I know by glancing at the odometer when my next service is due.

 

[iamdub]

when i do change the oil it be black as tar. not gunky its very thin just black. nothing like the clearish stuff that goes in. i ran it through a paint strainer once and ran a magnet over it nothing came up or was in the strainer except what looked like to be dirt.

Could just be high mileage (looser piston-to-wall clearances allowing more blow-by) and/or crappy gas. If you really wanna know, you could send a sample to Blackstone labs. You can request a free test kit from them. Tell them the basic info and they'll analyze the oil and tell you what all is in it and if you can run it longer or if you need to make a change somewhere. >CLICK HERE<

 

[ScottyBoy]

You guys would be surprised at how long you can actually go on an oil change with a GOOD synthetic oil and a good extended OCI filter. But like fun mentioned above, every situation and every vehicle is different. The absolute best way to tell is to keep getting a used oil analysis done. If you do an oil change at say 3000 miles and the sample test results basically say that the oil still has a lot of life left in it, then you would wanna go longer on the next oil change. Then get a sample of that next oil change tested, and say you went 6000 miles and the results say that the oil shows to still have about 30% of it's life left. Then go like 10,000 on the next one and the results say that the oil has exceeded it's lifespan. Then you would know after all those test that your sweet spot on your truck is about 7,500 miles. And that's exactly what my oil change intervals are. I use Amsoil XL Series oil and I change it every 7,500-8,000 miles because I had several oil analysis done and that's what seems to be the best for me. I only had three tests done, and I probably would have had much more conclusive results had I done more tests, but I basically know that 10k is the max for me so I change it at 7500. And just because oil is dark doesn't mean that it's bad or dirty. Yes used oil does get dark, but I've had some pretty dark oil tested and it was determined that it was still very usable oil. The old rule about changing it as soon as it gets dark doesn't really apply anymore either. But use common sense though, don't take that as meaning you can go 50k miles on an oil change. Lol
If changing it as soon as it gets dark, then that's fine and that's your choice. But I want to get the most out of my money, and if I can actually SAFELY go 7500 miles on an oil change then I sure as hell will even if my oil gets dark like root beer. Amsoil seems to be the best bang for my buck because I have a preferred customer account ($20 a year) and that gets me a considerable discount on my Amsoil purchases. I buy my oil by the case (12quarts) and it averages out to just under $6 a quart. That's less than pretty much any other brand of synthetic would cost me at a parts store. I was buying the Amsoil filters up until earlier this year. The Amsoil filters are about $13. I now grab a few of the Mobil1 Extended Performance filters from Rockauto whenever I place an order with them, because those are only about $6 at Rockauto. They are about $13-$15 pretty much everywhere else. I've seen some tests done and the Mobil1, Amsoil, and Royal Purple filters were basically the top filters you can get. Another side note, the Purolator PureOne filters also tested VERY well, so I would not hesitate to use that filter if you can't get a Wix or one the the three I mentioned above. Go check out Bobistheoilguy.com for more info about used oil analysis and about filter testing. I've learned a LOT from lurking over there.

 

[Windwalker]

I don't go cheap when it comes to my car. It might be overkill but I change my oil around 2000 miles. Might be dumb but it's my preference. Oil comes out with still a honey tint to it. Waste of money probably but worth it to me absolutely.

 

[swathdiver]

Agreed, and good story. I wonder if the engine in your racecar was getting stronger from the crank not hitting oil or maybe less oil pump drag?

That's what I figured as well. It ran its fastest times ever that night! Way back when, Mobil One had tv commercials showing engines freeze up as oil was drained from them while the engine with Mobil 1 kept on running. We proved that true more than once!

You guys would be surprised at how long you can actually go on an oil change with a GOOD synthetic oil...

My father's maintenance with cars is this, don't do anything to them! We changed his oil every 21k miles using M1 in an Olds Ciera with a Buick 3300. That engine was still running flawlessly when I gave the car away with 160k on the clock years and years later.

I don't go cheap when it comes to my car. It might be overkill but I change my oil around 2000 miles. Might be dumb but it's my preference. Oil comes out with still a honey tint to it. Waste of money probably but worth it to me absolutely.

Same thing for my race cars, at 1,500 to 2,000 miles it was coming out pretty clear still, honey colored is a great analogy.