My opinion stands.In my area 5w-30 motor oil is for cold (winter) and 10w-30 is for hot (summer).
10w-30 oil has a broader range of tolerance for heat than 5w-30 does and 5w-30 has a broader tolerance for cold than 10w-30 does.

"5w-30 is thinner than 10w-30. When it is cold it behaves like a 5-rated single grade oil, but will never thin more than a 30-rated single grade oil when hot."

I respect everybody's personal opinions and all that but the above statement is what I go by.Do what you want with your vehicles it makes no difference to me lol.
Honestly what you use is a matter of what the climate is in your area.I live in NY so it can get pretty warm in the summers and down right cold in the winter.
10w-30 or 5w-30 I don't think it makes that much of a difference really.For most people I don't think it will hurt your engine to use either.

I was not going to quote anybody but I changed my mind since I feel that the below statement is a bit of a personal challenge .

My answers:
0° Fahrenheit

I would say that if you were using 10w-30 at 0°, then you would technically be causing more damage than if you were using 5w-30 because once again 10w-30 is heavier and would flow less or slower at 0°.


212° Fahrenheit

Please enlighten me as to what vehicles other than maybe some hybrids come from the factory with 0w oil?
The 5w I believe you are right my Taurus owners manual calls for 5w-30 motor oil.However it also lists a handy chart for determining what grade oil would be best for different climates (temperature ranges).

I don't know much about 0w oils so I wont comment on them further other than to say unless you live in very extreme cold climates they are over kill and that they can be used to flush your motor. Since they are capable of not getting too viscous at such low temperatures one would reason that at operating temperatures they would be pretty thin.What little bit I did read about them stated that they are rated the same way as 5w oils so I guess I could be wrong but still would not run 0w oil in any of my motor vehicles because there is no reason at all for me to.if you are like Ruffnek from Canada then 0w oil could be a good option.

I don't know if all 0w oils are synthetic, you may be right on that but I can answer the rest of that question if you can tell me what auto manufacture does not get some sort of funding or kick backs from the oil companies for using/recommending one of their oil products.


I got all of my answers for the quiz from The Engine Oil Bible Happy reading.

 

A lot of euro stuff uses 0w xx. BMW and merc for sure, all were synthetic. I have worked at both dealers. My .02 I have seen vw use 1.5qts if the stuff in 5k(rep said "that's fine") on a new car that holds 4.5qts. 0w is thick water at best and a failed attempt at lower windage/higher milage.

 

My Acura TL-S uses 0w-20

 

A lot of non hybrid toyotas and hondas, are now coming factory filled a reccomended 0w20

 

That includes the 2011 Toyota 4runner factory fill and recommended @ 0w-20 synthetic..

 

was there ever a 2001 xj that came with 0w oil?

 

no

 

Use what the manual says.

 

Are 2011 API "SN" rated motor oils better than 2001 API "SJ" rated motor oils.........yep.

 

If it confuses you than justread the manual the xj came with or the oil cap really simple.As far as additive stp oil treatmeant has it,oil has it in it also but at a reduced amount. GL

 

hybrids are to his question

 

x2



one can only wish....

To bad for advancements in technology taking till 2011 for this to be the fill weight oil. **But** wait your in luck, you can buy the same 0w-20, 0w-30, or even 0w-40 oil today @ your local autoparts store and help your engine out.. whew!!!


Please elaborate on your explanation I highlighted above in bold...

I feel that I understand what you are meaning but you are missing the point. Both are the same @ Operating temp, same equals=same (30=30). What you are gaining is actually @ cold start or otherwise known as cold. To even make this crazier most 0w cold weight oils are a higher viscosity @ "cold" 40celsius than a 5w. But the 0w can go lower in temp than a 5w and maintain a crank-able pump-ability. This is due to a higher quality base being used in the 0w's.. This may not be the case with all 0w's and 5w's but is common to all that I have looked up.. I thought I was just crazy @ first.. (the verdict may still be ought on that)

I do feel that this is getting slightly off-topic from the OP though, sorry..

 

I'm going to continue to use Castrol GTX, I use 5W-30 in the winter and 10W-30 in warm weather. I've been using the same oil and the same method for probably 20 years. I and my family usually keep cars until they are too rusted out to maintain any longer. Typically, they have 200,000 miles on them or close to it.

We don't have any exotic sports cars, but I don't think XJ's qualify in that category anyway. In the 40+ years I've been driving, I've never had an engine failure that I can attribute to lack of lubrication. I have had a couple beaters blow up, but they were shot when I bought them.

 

http://www.bobistheoilguy.com/cms/in...d=84&Itemid=92

Just went back and did a little re-read of Motor oil by Dr A. E. Haas. 0W30, 5W30, 10W30 and straight 30 have the same flow rate and are the same grade (30) at operating temp (212F). The lower the 1st number, the less the oil thickens when the motor is off, starts to cool. The less the oil thickens at reduced temp, the quicker it will flow at start-up. Once operating temp is reached, all 4 of the above flow at the same rate. Read at least Motor Oil 102.

http://www.bobistheoilguy.com/cms/in...d=84&Itemid=92

 

An attempt to lure me into a whole other argument? :P Everything changes I cant argue against that .

I merely mentioned hybrids as part of one of my arguments against another statement that was made.My intention was not to make this topic about hybrids.The topic is not about BMW, either but they were mentioned for the same reason hybrids were mentioned.

I never disputed the fact that you can purchase 0w oils at your local auto parts store.

You basically just answered your own question.
I said I use 5w-30 in the winter and 10w-30 in the summer.I don't know but in my drive way during the winter months it is a lot colder than the summer months.So I use the 5w-30 because it is thinner and flows easier at the lower temps.I dont know how else to try and explain it.It is simple really.

I agree to some extent but this is what happens with every single oil thread I have ever seen. Oil is is confusing to a lot of us and there certainly are many different opinions and much info that makes it more confusing. I certainly do not mean to hijack or take this topic off track.I am only defending my opinions.

To give my opinion to the OP again, since you are from Cali I would just use a 10w-30.Anything else is unnecessary in my opinion

Re read my replies! I never stated that they were any different at operating temp.( I did contradict my self by saying) My fault I confused my self but I did in fact state the same thing you just did when I answered your questions.
djb383 I will gladly look through the link you provided.Looks like more good info.