Once I use synthetic motor oil in my car, is it fine to switch back to conventional motor oil.

I have a 95 325i w/ about 136k mi on it. The last time I had an oil change I opted for synthetic oil. It has been a long time and I am probably past due for an oil change. Very pricey for synthetic oil so I was debating of switching back to regular oil.

10/25/2006 4:17:55 PM

Not gonna hurt a thing.

You know you can run 5k+ miles on synthetic with no ill effects.

10/25/2006 5:00:39 PM

I usually run 5k on dino oil. no problems as of yet

10/25/2006 5:29:36 PM

10k on synth is no problem

10/25/2006 6:05:23 PM

what about 10k on dyno oil... jk i usually go 4-5k on dyno oil.

10/25/2006 6:11:21 PM

I run between 6 and 7k on the Cummins. but then it also holds about 13 quarts...

10/25/2006 7:16:50 PM

i'm going to start running 7,500 on synthetic - a normal filter can last that long right? or should I change the filter in the middle of the oil change and just add 1/2 quart to make up for the amount lost

i don't mind the extra cost of an extra filter but no need to throw money away

10/25/2006 7:46:25 PM

Quote :

"Based on the results we've got here, we'd recommend 8,000 miles between oil changes on an engine that uses no oil at all, perhaps 10,000 miles on an engine that uses some oil, and 15,000 miles or beyond with a filter change every 5,000 miles. This, of course, isn't any kind of guarantee, and you must evaluate for yourself what your engine requires. One thing we're pretty sure about though: 3,000-mile intervals is a huge waste of resources."

http://neptune.spacebears.com/cars/stories/mobil1.html

10/25/2006 7:57:37 PM

mobil and pure-one are selling a line of extended life filters now. I have yet to try one.

[Edited on October 25, 2006 at 7:58 PM. Reason : they cost twice as much, but they'll save you the time and hassle of changing one out]

10/25/2006 7:57:44 PM

i think i ran a little over 10k on this synthetic oil but i have not changed the filter during this period

i'm such a slacker

10/25/2006 8:49:53 PM

nm fuck synth.. ill go 5k with my dyno shit.

[Edited on October 25, 2006 at 9:26 PM. Reason : asfd]

10/25/2006 9:21:40 PM

^^i don't think that'll be any problem with synthetic. 10k is nothing.

10/25/2006 9:22:47 PM

Quote :

"Based on the results we've got here, we'd recommend 8,000 miles between oil changes on an engine that uses no oil at all"

Stopped to think about the fuckin tank of an engine that could do that before I read through it all

I do 5k minimum for synthetic and then change it before I do a roadtrip. Switching back aint no problem. I'd imagine it would help a little actually since the synthetic helps remove the sludge buildup.

10/25/2006 10:00:50 PM

From the same article I posted:

Quote :

"Engine wear actually decreases as oil ages. This has also been substantiated in testing conducted by Ford Motor Co. and ConocoPhillips, and reported in SAE Technical Paper 2003-01-3119. What this means is that compulsive oil changers are actually causing more engine wear than the people who let their engine's oil get some age on it."

Believe what you want.

10/26/2006 9:47:45 AM

Quote :

"I'd imagine it would help a little actually since the synthetic helps remove the sludge buildup."

synthetics don't do that.

10/27/2006 12:09:16 AM

Duh, gas does that. That and washer fluid.

10/27/2006 12:53:31 AM

mobil 1 in mine, oil changes every 15-20k, filter every 5 or so, no problems as of 192k miles

10/30/2006 3:45:31 PM

I wonder where the break-even point is for wear between running old oil and the dry starts that come with oil changes. it seems like changing it too frequently is going to cause extra wear from the dry starts, especially as an engine gets older and the tolerances increase.

10/30/2006 9:29:43 PM