# 0w40 oil?

**URL:** <https://forums.speedlife.net/t/0w40-oil/191649>\
**Category:** PittSpeed Automotive\
**Created:** [August 7, 2007, 12:32pm UTC](https://forums.speedlife.net/t/0w40-oil/191649 "2007-08-07T12:32:14Z")\
**Posts on this page:** 1\
**Showing post:** 11

<div class="post-metadata">

**Author:** ![dyingwish](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/dyingwish/32/6041_2.png) [@dyingwish](https://forums.speedlife.net/u/dyingwish)\
**Post date:** [August 8, 2007, 4:56am UTC](https://forums.speedlife.net/t/0w40-oil/191649/11 "2007-08-08T04:56:04Z")

</div>

> [@Saturn Vue](https://forums.speedlife.net/t/saturn-vue/31770/35):
>
> yea…engines that have run regular non synthetic oil their whole lives should stay that way…i think a rule of thumb is if your motor is over 70k DO NOT switch to synthetic

that isn’t necessarily true. Older seals and stuff will swell differently in synthetic than in dino oil, so you may have leakage issues. I wouldn’t make a blanket statment like that though.

---

_[View the full topic](https://forums.speedlife.net/t/0w40-oil/191649)._