if you use 5w40 after 5w30 can you go back?

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if you use 5w40 after 5w30 can you go back? #5279015 11/27/19 03:57 PM
Joined: Jul 2019 Posts: 19 EU P Polyalphaolefin OP
OP Polyalphaolefin P Joined: Jul 2019 Posts: 19 EU	Hello! I drive KIA Ceed 1.4 MPI, and alowed oil viscosities by the user manual are: 5w30, 0w40, 5w40, depending on climate. So, I plan to use 5w30 (or 0w40) on colder months, and 5w40 at summer. But I heard, once you switch to thicker oil (from 5w30 to 5w40) you can not go back to thinner (from 5w40 to 5w30). Any truth about that? Thanks Car: KIA Ceed JD 1.4 MPI OIL: 5w30 ACEA A5 / A3; 5w40 ACEA A3; 0w40 ACEA A3

Re: if you use 5w40 after 5w30 can you go back? [Re: Polyalphaolefin] #5279018 11/27/19 04:00 PM
Joined: Dec 2018 Posts: 562 Vancouver J Jimmy_Russells
Jimmy_Russells J Joined: Dec 2018 Posts: 562 Vancouver	Originally Posted by Polyalphaolefin Any truth about that? No

Re: if you use 5w40 after 5w30 can you go back? [Re: Polyalphaolefin] #5279021 11/27/19 04:01 PM
Joined: May 2012 Posts: 3,423 The land of USA-made Subies! SubieRubyRoo
SubieRubyRoo Joined: May 2012 Posts: 3,423 The land of USA-made Subies!	You can freely use any oil that meets the specifications in your owner's manual regardless of weight.

Re: if you use 5w40 after 5w30 can you go back? [Re: Polyalphaolefin] #5279022 11/27/19 04:01 PM
Joined: Jul 2018 Posts: 63 Europe M Mitsu_Joe
Mitsu_Joe M Joined: Jul 2018 Posts: 63 Europe	True! I am at this point running 500w-1200 in my thirty year old car as I always prefer switching to a thicker oil during summer. ;-) Joking aside, there is no scientific background to that. The viscosity choice you made (5w30 in winter, 5w40 in summer) seems very fitting and should work perfectly fine. Last edited by Mitsu_Joe; 11/27/19 04:01 PM. 1988 Mitsubishi Galant, Meguin SL 5W-40

Re: if you use 5w40 after 5w30 can you go back? [Re: Polyalphaolefin] #5279026 11/27/19 04:03 PM
Joined: Feb 2016 Posts: 50 NY J jqgz
jqgz J Joined: Feb 2016 Posts: 50 NY	No issues. Just change it regularly and use a good filter.

Re: if you use 5w40 after 5w30 can you go back? [Re: Polyalphaolefin] #5279036 11/27/19 04:12 PM
Joined: Dec 2017 Posts: 3,063 CO J JLTD
JLTD J Joined: Dec 2017 Posts: 3,063 CO	Originally Posted by Polyalphaolefin But I heard, once you switch to thicker oil (from 5w30 to 5w40) you can not go back to thinner (from 5w40 to 5w30). Any truth about that? Thanks No truth involved. Whoever told you that is....shall we say, misinformed. I use the overseas manual to choose my viscosity. Hers: 2008 Jeep Liberty 154k, SS 5w30/Amsoil Looking at options. His: 2015 4Runner 60k, SS 5w20/Amsoil

Re: if you use 5w40 after 5w30 can you go back? [Re: Polyalphaolefin] #5279041 11/27/19 04:19 PM
Joined: Nov 2008 Posts: 14,936 NH S supton
supton S Joined: Nov 2008 Posts: 14,936 NH	Switch away freely. 2011 Toyota Camry, base, 2.5L/6MT, 198k, hers 2010 Toyota Tundra DC, 4.6L/6AT, 156k, ours 1999 Toyota Camry LE, 2.2L/4AT, 219k, his

Re: if you use 5w40 after 5w30 can you go back? [Re: Polyalphaolefin] #5279481 11/28/19 07:12 AM
Joined: Aug 2018 Posts: 64 South Carolina M mpack88
mpack88 M Joined: Aug 2018 Posts: 64 South Carolina	I used traveller 10w30 Dino in a 85 Chevy caprice wagon 305v8 that always got 20w50. It runs better on the thinner weight and puts more power out. However it does seem to leak more. Car has over 400k miles.

Re: if you use 5w40 after 5w30 can you go back? [Re: mpack88] #5279566 11/28/19 08:58 AM
Joined: Oct 2004 Posts: 9,725 Cincinnati, OH, USA B bullwinkle
bullwinkle B Joined: Oct 2004 Posts: 9,725 Cincinnati, OH, USA	Originally Posted by mpack88 I used traveller 10w30 Dino in a 85 Chevy caprice wagon 305v8 that always got 20w50. It runs better on the thinner weight and puts more power out. However it does seem to leak more. Car has over 400k miles. Holy carp! How many camshafts, carburetor rebuilds, and sets of valve seals did it take to go that far? (Might be able to tell I've had a few pre-EFI Chevy SBs) 06 Ram 3500 CTD 4X4(FG Venturi), 93 GMC C3500 6.2, 89 F-450 7.3, 98 XJ 4.0(XG8A), 05 xB(XG3600), 18 Transit 3.7, 03 Merc Grand Marquis 4.6 2V(XG2)

Re: if you use 5w40 after 5w30 can you go back? [Re: Polyalphaolefin] #5279578 11/28/19 09:11 AM
Joined: Feb 2005 Posts: 1,968 Arizona B bulwnkl
bulwnkl B Joined: Feb 2005 Posts: 1,968 Arizona	Originally Posted by Polyalphaolefin I heard, once you switch to thicker oil (from 5w30 to 5w40) you can not go back to thinner (from 5w40 to 5w30). Any truth about that? Thanks No. I went from 0w20 to 5w20 to 5w40 and back to 0w20 recently. No issues. The engine doesn’t care. I use speech recognition frequently. Please excuse any consequent grammatical or typographical errors.

Re: if you use 5w40 after 5w30 can you go back? [Re: Polyalphaolefin] #5279586 11/28/19 09:20 AM
Joined: May 2019 Posts: 2,974 WA M Mad_Hatter
Mad_Hatter M Joined: May 2019 Posts: 2,974 WA	Originally Posted by Polyalphaolefin Hello! I drive KIA Ceed 1.4 MPI, and alowed oil viscosities by the user manual are: 5w30, 0w40, 5w40, depending on climate. So, I plan to use 5w30 (or 0w40) on colder months, and 5w40 at summer. But I heard, once you switch to thicker oil (from 5w30 to 5w40) you can not go back to thinner (from 5w40 to 5w30). Any truth about that? Thanks No, no truth whatsoever. And it sounds like a solid plan. But remember, once you go thick you may never go back!😂 Last edited by Mad_Hatter; 11/28/19 09:23 AM.

Re: if you use 5w40 after 5w30 can you go back? [Re: Polyalphaolefin] #5279990 11/28/19 07:49 PM
Joined: Apr 2012 Posts: 11,545 Kendall, FL W wemay
wemay W Joined: Apr 2012 Posts: 11,545 Kendall, FL	I do it in my wife's 2.0T all the time. Zero issues 2018 KIA Sportage LX AWD Shell RGT 5W20, STP S2808 2013 Hyundai Santa Fe Sport 2.0T M1AP 5W30, M1-104

Re: if you use 5w40 after 5w30 can you go back? [Re: wemay] #5280029 11/28/19 09:18 PM
Joined: Aug 2008 Posts: 2,760 Cali Malo83
Malo83 Joined: Aug 2008 Posts: 2,760 Cali	PP 5w30 year round in my 2.0T, no need for musical oils.

Re: if you use 5w40 after 5w30 can you go back? [Re: Polyalphaolefin] #5280094 11/29/19 12:30 AM
Joined: May 2019 Posts: 2,974 WA M Mad_Hatter
Mad_Hatter M Joined: May 2019 Posts: 2,974 WA	Originally Posted by Malo83 PP 5w30 year round in my 2.0T, no need for musical oils. The OP could just run a thick, +11/+12cSt Xw30 year round and not have to do the musical oils.😉 I know he's in the EU but the Havoline 5/30 HiMi SB I run from time to time is a 11.8cSt lube. "But what about CAFE"...meh, never heard of her!😂 Last edited by Mad_Hatter; 11/29/19 12:32 AM.