You're not going to notice stuff like that from leaving old oil in too long. The damage is done over time with a shortened engine life. I'm sure the next person that gets your dads vehicle would love to know the kind of TWISTED experiment you did to their new (to them) vehicle. Way to go!

 

LOL, you make it sounds so horrible to keep an oil ment for 15k miles of life in the engine for 15k. Again, I may just change it at 10k or sometime around there.

 

http://www.mobiloil.com/USA-English/...AQs.aspx#FAQs3

 

Good luck trying to collect on that one It's your car.... Um your dad's car. Do what you want. You'll learn as you get older that you can't believe everything that you read.

 

^^ agreed!!

 

I'm not saying it's true, I'm just saying it's what Mobil 1 is promising so we'll see where it gets me. I plan on changing it a year from the day I changed the oil, so about 12k miles.

 

Why are you posting this here? You obviously don't care about the car or anyone that may buy it so why even change the oil? Just top if off when it gets low...

 

I'm posting this here because someone asked how long people keep their extended performance oil in and I answered. I do care about the car and I'm choosing to belive what Mobil 1 is saying and see how it works out for me when I change the oil after 1 year/12k miles. I change the oil because my dad wants the car to keep running and for it to be in good condition. By changing his oil with a very expensive high quality synthetic oil that is promising 15k miles of use, I don't forsee any harm being done to the engine, however if when I change the oil it comes out incredibly black and dirty, I will never change it at 12k again and continue doing routine 5k changes. I don't think changig it ONCE with this oil at 12k will do any longterm harm...

 

What does a guarantee to protect your motor for 15,000 miles mean? It means the motor is guaranteed not to suffer undue wear with 15,000-mile oil change intervals. It means that it will suffer no worse wear than a motor run on petroleum for the mfr's recommended interval of 5,000 or 7,500 miles. That is Mobil's promise to you. Nothing more.

The US carmakers have 7,500-mile oil change intervals and Mobil 1 doubles that. Scion has a more frequent 5,000-mile oil change interval, which may mean that Mobil's promise is cut to 10,000 miles for our xBs.

But synthetic oil gets dirty the same as petroleum oil - it just has more detergent additives to hold everything in suspension as it goes 'round and 'round. At 5,000 miles conventional oil in the xB is black and smelly. Imagine what Mobil 1 would be like at 10,000 miles.

If you like to keep your engine clean, and want your xB's engine to last for a very long time, change petroleum oil at 3,000 and synthetic oil at 5,000.

 

Have you ever checked your oil before? It's incredibly black and dirty after just 2k miles. Trust me, you don't have to wait until 12k to find out.

 

AGGHHH, I'm being bombarded by people that are against me! I payed $40 for a top of the line oil, and I plan on using it to it's potential..jeez you guys, I don't see what's so wrong about keeping an oil that is tested to still work well in the engine at 15k miles, in my engine for 12k miles.

Vintage42: What you just said about Mobil 1s gaurantee is all I'm asking for from Mobil 1, nothing more. And just FYI, I don't have an xB, I'm acually talking about my dad's oil in his '02 Buick Rendevouz as mentioned above.

 

First, the purpose in my mind in using better oil is to change it BEFORE it is in the same condition as conventional oil is after 3k. If not, you really arent saving yourself much of anything. Actually you are worse off since you are closer to its threshold for a higher number of miles. So basically you are running closer to its poor performance line for many more miles since it tends to break down in a somewhat linear fashion.

I dont run mobile1 cause I can change it at 7k and have it in the same condition as conventional oil is after 3k.. I do it so when I change it at 4k it is in BETTER condition. And as mentioned, you would NEVER prove that it caused issues.. the issues will arise down the road in the form of premature wear.. just like many "garaunteed" products and mods.. that is why they are willing to warranty them so well. The warranty is useless. And running it longer between changes really only saves you a noticeable amount of money if you pay someone else to change it. You could buy regulare mobile 1, change it yourself every 4k, and still be better off both monetarilly and mechanically.

And some clarification.. maybe a minor detail.. but synthetic oil IS petroleum. The same oil is broken down into the parts you need and the rest is discarded.

 

I'm not saying it's great to run the oil for 12k. What I am saying is that I purchased a $40 top of the line oil proven to be good for 15k miles and I don't see any purpose in draining it at 5k. If people were having serious problems from using an oil made to last 15k miles, for 15k miles they would stop buying it and Mobil would stop producing it. I know the oil will be dirty when I change it, the point is is that it won't be so dirty to a point to where I harmed my engine., that's Mobil 1's promise. And FYI, I never planned on using the "gaurantee" because you guys are right, you can't prove anything with it.

 

I just don't see the point of paying big bucks for oil just to extend oil changes. Changes every 5K with Mobil1 is just cheap insurance, Period.....

 

http://www.mobiloil.com/USA-English/...y_Winners.aspx

There's tons of testomony's in there from people that have used the oil from 10-15k with no problems whatsoever. I know it's a Mobil run site but still, I don't see any reason for them to make it all up because if they did lie and people where harmng their cars they would loose more money then they made because people would just stop buying their products. I'll take some pics of the oil for you guys next year when I drain it.

 

hmm.. all this talk about oil lasting long... uhh... we forgot to mention the filter....

 

To tell you the truth, this was my 1st time changing the oil in any car, so I decided to buy the highest quality stuff I could find, I figured if it's ment for extended use it has more cleaning agents and will clean up the crap oil the shops have been using on the car for the past 40k miles. After hearing how many of you are against the extended drain intervals, my next oil change for my car, and my dad's car if he ask's me to do his, will be using normal Mobil 1 for 5k miles.

 

AGHH, Just as I finish answering 1 comment another one pops up, I can't keep up with you guys! I'm using the Mobil 1 Extended Performance filter so it should last for as long as the extended performance oil...It was like $12 so it better last!

 

That extended junk hasn't been out long enough for the damage to surface. Using this stuff is like making your vehicle a guinea pig. I'm glad you decided to do right by your dads car. Thank You!!!

 

I'm sure there's people that have used it who drive 30k a year and change their oil twice a year. For example people who drive far to work everyday and don't have time to change their oill frequently but still don't trust mechanics to do it for them.