# RPM Fluctuation **URL:** \ **Category:** Maintenance/Repairs\ **Created:** [June 21, 2008, 8:38pm UTC](https://community.cartalk.com/t/rpm-fluctuation/15662 "2008-06-21T20:38:57Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![EYHPETE](https://avatars.discourse-cdn.com/v4/letter/e/b38774/32.png) [@EYHPETE](https://community.cartalk.com/u/EYHPETE)\ **Post date:** [June 21, 2008, 8:38pm UTC](https://community.cartalk.com/t/rpm-fluctuation/15662/1 "2008-06-21T20:38:57Z")
My 2000 Chevy S-10 4x4 has been driving rough for a few weeks. The tac revs up and down while I’m driving - feels like it’s losing power, then catches and continues on normally. I just put new tires on it (31 10.50 - the same size as the ones that came on it) but I’m not sure the problem is related. Any ideas? ---
**Author:** ![irlandes](https://avatars.discourse-cdn.com/v4/letter/i/b5e925/32.png) [@irlandes](https://community.cartalk.com/u/irlandes)\ **Post date:** [June 22, 2008, 4:24am UTC](https://community.cartalk.com/t/rpm-fluctuation/15662/2 "2008-06-22T04:24:38Z")
I have no idea how new tires same size could cause rough running. Do I understand that when you are under power, as opposed to coasting to a stoplight or otherwise reducing power, it runs rough at times? I ask to eliminate the possibility of an idle control problem, but for sure that would not be the case when you have the throttle down a ways, only when you let up on the throttle in normal driving where speed varies in traffic. Just want to make sure we are speaking the same terms. ---
**Author:** ![Xebadaih](https://avatars.discourse-cdn.com/v4/letter/x/d07c76/32.png) [@Xebadaih](https://community.cartalk.com/u/Xebadaih)\ **Post date:** [June 22, 2008, 6:21am UTC](https://community.cartalk.com/t/rpm-fluctuation/15662/3 "2008-06-22T06:21:48Z")
Automatic or manual? Sounds to be a transmission issue.