# Synthetic oil vs. mineral (regular) oil

**URL:** <https://community.cartalk.com/t/synthetic-oil-vs-mineral-regular-oil/56721>\
**Category:** Maintenance/Repairs\
**Tags:** bmw, 528\
**Created:** [October 23, 2010, 3:27am UTC](https://community.cartalk.com/t/synthetic-oil-vs-mineral-regular-oil/56721 "2010-10-23T03:27:34Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![ithaca2007](https://avatars.discourse-cdn.com/v4/letter/i/ecb155/32.png) [@ithaca2007](https://community.cartalk.com/u/ithaca2007)\
**Post date:** [October 23, 2010, 3:27am UTC](https://community.cartalk.com/t/synthetic-oil-vs-mineral-regular-oil/56721/1 "2010-10-23T03:27:34Z")

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I have a 1998 BMW 528 and I used synthetic oil once. Can I switch back to regular oil?

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**Author:** ![tardis](https://avatars.discourse-cdn.com/v4/letter/t/f0a364/32.png) [@tardis](https://community.cartalk.com/u/tardis)\
**Post date:** [October 23, 2010, 3:30am UTC](https://community.cartalk.com/t/synthetic-oil-vs-mineral-regular-oil/56721/2 "2010-10-23T03:30:25Z")

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You can switch back and forth as much as you want. Just make sure that you use oils that meet BMW’s spec for your car.

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**Author:** ![the\_same\_mountainbike](https://avatars.discourse-cdn.com/v4/letter/t/c89c15/32.png) [@the\_same\_mountainbike](https://community.cartalk.com/u/the_same_mountainbike)\
**Post date:** [October 23, 2010, 12:02pm UTC](https://community.cartalk.com/t/synthetic-oil-vs-mineral-regular-oil/56721/3 "2010-10-23T12:02:18Z")

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You can switch back and forth and even blend them if you’d like.

Synthetic oil and regular oil are chemically exactly the same. The differences are that synthetic has more consistant molecule sizes (allegedly, I’ve never actually seen them) and fewer impurities.

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**Author:** ![lion9car](https://avatars.discourse-cdn.com/v4/letter/l/59ef9b/32.png) [@lion9car](https://community.cartalk.com/u/lion9car)\
**Post date:** [October 23, 2010, 2:34pm UTC](https://community.cartalk.com/t/synthetic-oil-vs-mineral-regular-oil/56721/4 "2010-10-23T14:34:03Z")

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Are you sure your car allows conventional oil? I know that the 5-series a few years newer than yours requires synthetic oil.