Do cars in the summer need thicker motor oil? Please answer, I need this info for my sci. project on viscosity

Thanks!!





p.s: Does it go vice versa too? Like in the winter=thinner oil or something?


:)Do cars in the summer need thicker motor oil? Please answer, I need this info for my sci. project on viscosity
look at your owners manual most of them show a graph





i always protect from heat as the cold start up is only a minute or so look at what temp the highest temp you anticipate before your next change and use that oil





i ruined an engine on a vw rabbit water cooled engine i took advice from a oil expert and added 10w 30 oil it cooked in about 1 month as the oil broke down the outside temp was in the upper 90's the owners Manuel stated 10w30 shouldn't be used above 75





i always protect for heat now i use 15w 40 oil year round i idle the engine for a minute on cold mornings to get things warmed upDo cars in the summer need thicker motor oil? Please answer, I need this info for my sci. project on viscosity
Grab almost any owners manual and look in the customer data area there will be a thermometer illustrated there with viscosity chart showing -35 degrees 0wt-, 5wt-30 at the bottom and and as temp averages go up slightly heavier oil at 100 degrees 10wt-40. 15wt-50 and so on. In the artic -60 degrees they do not turn off engines because they will not restart. Super cold temps need oil that won't freeze solid and still flow.
Yes they do.


http://auto.howstuffworks.com/question16鈥?/a>
Here's a reference that should help you.





http://www.carbibles.com/viscosity.html


http://www.carbibles.com/engineoil_bible鈥?/a>
In the winter I put 5W-30 in my miata and 10W-30 in the summer. Yes thicker oil is recomended in the hotter temperatures.
I would have to say no. All cars run at a constant temperature when the car is fully warmed up. (160-190) So it wouldn't matter on the viscosity. Now if you are talking about an air cooled engine yes it would matter. Air cooled engines use outside air to cool the oil to keep the engine from overheating.
With the multi-viscosity oils that we have today no you do not need to, but the simple answer to your question is yes they do.
Decades ago, yes. Today most vehicle manufacturers recommend the same weight of oil all-year round with the most common being 5W30 and 5W20.
The oil needs to have less resistance to flow at colder temps. Oil has to flow and during the winter the wrong grade oil can keep an engine from starting.


But as the engine warms up (and the oil also) because of chemistry it has a greater chance of failing.


So multi-grade oils were developed to provide the protection an engine needs when hot while not interfering with ability to turn over when cold,
yes,they do

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