What are the pros and cons of these two oil weights? I live in STL and temps around here get down to approx. 3 degrees but rarely lower. This is towards the lower end of the operating range of 10W-30 weight oil (according to the manual), so would you recommend going with 5W-40? What is the downside of putting 5W-40 into your car? Does 5W-40 provide less protection in warmer temperatures? Thanks for the help!

 

This is just an opinion. But even in the colder months at start-up, the 10w30 should circulate a little easier then the 5w40 over the range of full cold to fully warmed up. Maybe a better comprimise in the cold winter months would be 5w30.

 

I'm interested in knowing the benefits for running 40. What are they?

 

Here temps get pretty low too, but I store my car for the winter, so the lowest temp it sees on starts is 30 deg F. I still use a 5W-40 just to get a lower viscosity on startup. The 40 weight theoretically gives better lubrication for hard runs, although it may give you worse gas mileage

 

WHY keep posting this? There is a FAQ devoted to this issue as well as thousands of posts. We will get the usual ignorance, random speculation, and then ads for favorite brands (amsoil pays me to advertise, but I prefer redline).

1. Use 10W30. Get a high quality synthetic and use testing to determine you oil change frequency based on TBNs. I use blackstone to test. BITOG will tell you more than you ever want to know (use google ffs).

2. Cold temperature pumping flows at 10W30 on any decent oil are below your ambient. If you live in Canada or the Rockies/Sierras, run synthetic and have a low pour point.

2. "The 40 weight theoretically gives better lubrication for hard runs." On the planet zatr this might be true. On this planet, bearing film thickness based on Honda's engineering say 30 for this engine's clearances.

 

Yep, and there you are with your ignorance that mucked up every other oil thread . Can't you share your ideas/knowledge is a mature constructive way??

If I am not mistaken we already went back and forth on this issue and I am not doing it again.

OP, sorry you got this "you should have searched attitude" from some member who thinks that because they have been a member for longer than you and has the time to average 9.8 posts a day they are better than you.

5W40 works just fine in our engines, IMO, it works better than 10W30 for where I live and what I do with my car. Just give it a try if you don't like it switch back.

 

Up in Canada 5W40 is perfect for our cold winters as well as running the car hard on the track during the summer.

You could read all day about the right weights for our car. Just make life easier for yourself, look at the info in the manual and make your decision using the little graph.

 

Again, RTFM, RTFF, and BITOG for that matter and come back with a real question. As far as the random usings of the ill-informed, the difference between engineers and stupid people is that engineers test their assumptions and stupid people guess.

 

^^

what the hell does all that mean?


if the VP is such a VIP dont you think the VC would want him KIA so we should keep it on the DL?

 

I say try them both and see which one you like better. Either one should work well for your situation. Then report back and tell us what you think.