amlin423

Guys...I was curious as to whether a car really needs an oil change that often...My gf's cousing said her bmw manual recommends 15K change intervals whereas my gs recommended 5000...i also had a nissan that recommended 7500 if I remember correctly...anyhows...such vast difference prompted me to do some search and the place i usualy go to is www.howstuffworks.com It's really a great site if you have never been there... Check out this link and see what you guys think of this....

http://www.motor-oil-bible.com/index-test.html

I did spend the 10 bucks to get the e-book and i must say it sounded convincing...I know Mene Gene is a petroleum engineer (i read that before here) and maybe he can see whether or not this book is BS or not.

Mean Gene

A - I don't have that book so I'm not sure of it's contents - might pick one up & write it off as "continuing educational training material" . Under "normal" driving, conventional oil drain intervals of 3000-3500 aren't necessary, IMO. Technically, oil doesn't wear out - it just becomes contaminated with dirt & combustion byproducts. U may remember a post a few months back where I mentioned the STP oil of the late 70's - it claimed to have a useable lifespan of 25k miles. If ya read the fine print, U still needed to change the filter every 5k or so & this was a conventional petroleum based oil & not the advanced synthetics we have today. In our harsh offshore environment, we only change our oil every 3000 hours of run time ( typically once every 3-4 months on equipment that runs 24/7 ). However, the filters R changed ( on certain equipment with non-syn lubricants ) every 1000 hours or so. On the air compressors running synthetic Royal Purple, we step up to a 6 month change service interval. I still believe in synthetics over conventionals & it seems like this book does also, judging from the paragraphs I read over. For MY needs ( based on my driving style ), I change the filter every 5k & the M1 5W-30 every 10k - same advice I got from Lingenfelter regarding my 'Vette.

Erfan

how can you change the filter without all the oil dripping out?

CSHFLW

That was my question???

Mean Gene

Guyz - Without trying to seem like a smart ***, U just unscrew the filter. The lubrication system is pressurized & requires the oil pump to be operating to overcome a check valve upstream of the oil filter housing ( keeps the oil from backflowing ). The only oil U'll lose is what's in the filter & maybe a few drops up in the filter housing area. No worries!!

black sc

I have a question regarding extended oil changes for conventional oil or natural base stock oil. Is it ok to extend the maintainence on these especially if, it is 5W-30 or 15W-40. I change out the filiters (OEM) and oil every 3000K but, was wondering if the parafins in the oil will cause any sludge build up? If I extend it to like 7000K-10000K miles and change out the oil and change out the filter every 3000k miles. Is it ok or is that bad for my engine? I am asking because, I read several testimonials in the BMWCCA magazine about 10 years ago that, you don't even have to change the oil just, the filter element and they weren't even using synthetic oils. They testified to driving 80K-120Kmiles on natural based stock oil and it was not an advertisement. They only changed out the filter element every 5000K-7500k miles not, the oil. It was in the Roundel magazine's editorial and tech sections. They ran oil analysis and results came back with a clean bill of health. However, I never really believed in that but, I am beginning to wander. I read up in some ECE recommendations saying to do oil changes every 9000k miles now. Am I wrong or am I just starting to believe everything I read? Help me out in this confusion

Erfan

I change my oil every 3000k miles anyway, it is so cheap, $20 every 6 months is nothing for me.

mooretorque, thanks for your input, I just wasnt clear on how that was possible, but now i know.

Thanks

Erfan

CSHFLW

On my BMW they say every 15K miles for oil change.....

Mean Gene

Black - Since oil doesn't really wear out ( within reason ) but simply gets dirty and/or contaminated with combustion byproducts, I don't see any problem with extending your change intervals to 7500 - 10k as long as U do the filter change as U mentioned. The SAE has tightened up their allowances on paraffin content so it's not as much of a factor as it used to be - remember the old Quaker State oils? U could always tell who ran QS just by sticking your finger in their valve cover & if it was covered in sludge, U knew!!:eek: Even years ago when the oil quality wasn't as good as today's lubricants the factory would specify 7500 mile change intervals so I'd feel safe doing it today even if I wasn't running Mobil 1.

black sc

Thanks Mean Gene for the response. That is what I wanted to know. Heard about Quaker State's parafin content. I heard the same with Penzoil but, just rumors. I also heard it depends on the kind of esther stock they use varies also and will cause sludge.

Regarding Quaker State, I heard about a mechanic who took apart a engine and they had to use a putty knife to take off the sludge off the inside. That's pretty bad. he was using QS. Thanks again.

Erfan

Does Pennzoil have paraffins which cause sludging while other brands don't?

Sludging is prevented by, not caused by, the use of paraffinic oils. Pennzoil as well as all other major motor oil producers use paraffinic base oils to produce motor oil. This type of base oil has advantages over the other types of mineral oil available, which is why they are universally used. The only exceptions are synthetic motor oils, which of course cost much more than mineral oil based motor oils. Synthetic base stocks are 100% paraffinic. Technically, paraffinic oil is a term used to describe the chemical structure, not the wax content. Through dewaxing in the refinery and the addition of pour point depressants during blending any harmful effects of wax are eliminated or neutralized.

This is straight off of the Pennzoil web site under the FAQ's section.

Thanks

Erfan