10w30 in the summer, 10w40 in the winter? Is that ok?

Messages
1
Location
Nashville, TN
I have been changing my own oil since 1988 (18 y/o w/a 1979 Chevy Van). Then I went to a '90 Cavalier Z24, then a '94 Gran Prix, then a '90 240SX, '01 Olds Alero and now a '00 Max. All this time I have been of the mindset: 10W30 in the winter, 10W40 in the summer. Living in TN, I always liked the thought of offering better protection by switching to the thicker oil in the summer. Should I continue this practice? Or modify it? You thoughts & comments please. Thanks in advance. [ May 21, 2003, 02:28 AM: Message edited by: billyman ]
 
Messages
1,856
Location
PA
I don't see the advantage of such a practice so long that the 30 is enough viscocity. You don't want too little or too much, and only an analysis can tell you whether a 30 or 40 is better for summer/winter. I run 10W-30 no matter what right now. I have heard running 10W-40 can cause a car to never run right on 10W-30 later on, but again these are rumors and are not likely true [Smile] Looking at your situation, it appears they aren't at least.
 
Messages
453
Location
Galveston, TX
quote:
Originally posted by Dominic: I run 10W-30 no matter what right now. I have heard running 10W-40 can cause a car to never run right on 10W-30 later on, but again these are rumors and are not likely true [Smile] Looking at your situation, it appears they aren't at least.
From 1999 to mid- 2002, I used 10w-40 regardless of season or weather, regardless hot or cold. From mid-2002 to December 2002, I used straight grade HD-30 mineral oil in hot summer weather and 5w-30 in cold winter weather. For my next oil change, I will pour in either 10w-30 or 10w-40. My car is 38,500 miles and 4 1/2 years old.
 

Patman

Staff member
Messages
21,990
Location
Oakville, Ontario
I would say pick a good 5w30 or 10w30 synthetic and stick with it year round. No need for 10w40 with your car, the clearances most likely are tight enough that 40wt oil is too thick for best engine wear.
 
Messages
179
Location
Forest Hill MD
quote:
Originally posted by billyman: 10W30 in the winter, 10W40 in the summer.
Tennessee has winter?!?!? You could probably run 10W-40 all year round. Just make sure it's a synthetic.
 
Top