Does it really matter how hot it is outside?

[FL-400S]

My 3 older cars take 5w30. The newest (09 vibe) takes 5w20. I had the free oil changes from pontiac dealer last year, and they put in 5w30, even though the coupon says "recommended grade." I dont really mind, but questioned them and they said its because it is so hot here, we need a thicker grade (deep south). I tend to think it doesn't matter how hot it is as long as your cooling system is working. I had it changed in December (castrol 5w30) and on a recent road trip got 32 mpg (rated 31, I tend to drive the speed limit). I'm back to doing the oil changes again in a few months and I'll put in 5w20 because I already have some. But does it really matter what grade depending on outside temperature, so long as your cooling system is working normally?

I typically change the oil and filter on the vibe about every 6-12 mos which would be 5-7k miles. I'll tend to use syn so I dont have to worry about it as often. Driven about 50% town and 50% highway.

 

[JeremyInMT]

This is covered really well by "Motor Oil 101" on the front page of this site; at least better than I could, but I'll try to summarize. The answer is no on the hot end but it could on the cold end of things. Check out the main page. It's a terrific read.

 

[d00df00d]

Your cooling system keeps your engine cool, but not your oil (on most cars). If it's hot out, your engine and coolant might be fine, but your oil will still be hotter.

That's why some people argue that you need a thicker grade for hot climates. In reality, it depends on the application (what you drive and how you drive it), as well as the oil in question (dino vs. synthetic, different formulations, etc.).

You say your car specs 5w-20, but received 5w30. Are both grades allowable for your car, or does your owner's manual specify only 5w-20 for all climates? Also, what other information is specified (API/ILSAC certifications, etc.)?

 

[rshunter]

The real question is whether GM and Toyota ever expected the vehicle to be sold and/or used south of the Mason-Dixon line when they made the decision to recommend 5W-20. I'm going to take a wild guess and say "YES".

 

[asamek]

yes, your oil will be a little hotter - but not enough to cause any sort of concern.

The cooling system maintains a relatively consistent internal environment for your engine, through which the oil moves. The "hot spots" are there regardless, and don't get significantly hotter because of outside ambient temps.

 

[demarpaint]

If the OM states 5W20 and no other options I would have them change it on their dime. If more than one choice was given then I'd live with what they used. In think in this case the dealer got a better price for 5W30 and is using it to up his bottom line. Will it matter? I don't think so.

I'm pretty confident in the 20 grade oils, and I feel it has been extensively tested in engines calling for it, even under extreme conditions. There is a great read, [I wish I could find it] on the testing Ford did with 5W20 oil. It works quite well in Ford applications calling for it.

 

[HBCALI]

Originally Posted By: demarpaint
In think in this case the dealer got a better price for 5W30 and is using it to up his bottom line. Will it matter? I don't think so.


+1

Have no fear, 5w30 compared to 5W-20 is not a huge deal. IMHO, It's just the principal behind why the dealer used it. I would simply go 3,000 (or less) and change the oil with a high qaulity 5W-20.

Here's my two cents:

You didn't ask for the dealer's opinion - you asked for an oil change. The dealer really has no valid reason to use an oil unspecified in your manual. Does your manual recommend using 5w30 if your vehicle is operated in the Southern U.S. or where daily temperatures exceed "X" degrees? Probably not. So I guess that would mean the "dealer" has become more of an expert than the OEM? Interesting...

Sorry If I sound negative, I just dislike the "song and dance" mechanics like to push on people. Happens to me (or least they try) all the time. Reality check: I could care less what deal they got on "Bulk" oil, not my problem. However, it becomes my problem (and thiers) when they make up silly excuses to justify shotty service.

 

[eljefino]

The difference between 210'F and 100 or 80 isn't that much.

But as humans at 98.6, we really suffer at 100 while 80 is darn pleasant.

Since we suffer, we vainly believe the machinery must be suffering as well.

 

[FL-400S]

Originally Posted By: HBCALI
Originally Posted By: demarpaint
In think in this case the dealer got a better price for 5W30 and is using it to up his bottom line. Will it matter? I don't think so.


+1

Have no fear, 5w30 compared to 5W-20 is not a huge deal. IMHO, It's just the principal behind why the dealer used it. I would simply go 3,000 (or less) and change the oil with a high qaulity 5W-20.

Here's my two cents:

You didn't ask for the dealer's opinion - you asked for an oil change. The dealer really has no valid reason to use an oil unspecified in your manual. Does your manual recommend using 5w30 if your vehicle is operated in the Southern U.S. or where daily temperatures exceed "X" degrees? Probably not. So I guess that would mean the "dealer" has become more of an expert than the OEM? Interesting...

Sorry If I sound negative, I just dislike the "song and dance" mechanics like to push on people. Happens to me (or least they try) all the time. Reality check: I could care less what deal they got on "Bulk" oil, not my problem. However, it becomes my problem (and thiers) when they make up silly excuses to justify shotty service.

Yeah that was my attitude. Knowing that they wont always be doing the oil changes, I dont sweat it. If I continued to go there I would probably make them put in 5w20. Since I'll be doing it, Ill do what I always do--put in what it says on the filler cap (5w20). It would be nice to only stock 5w30 in the garage, but this car takes 4.5 quarts which makes a 5+ quart jug more than enough. Plus I want maximum mpg if possible. I didn't buy a 1.8L to roast tires or tow.

 

[IndyIan]

Originally Posted By: eljefino
The difference between 210'F and 100 or 80 isn't that much.

But as humans at 98.6, we really suffer at 100 while 80 is darn pleasant.

Since we suffer, we vainly believe the machinery must be suffering as well.

I think if you crunched the numbers though on heat loss out of the oil pan with ambient temps at 80F and 100F you'd find there is significantly less heat moving out of the pan at 100F than 80F. Go up to 120F on a hot grid locked freeway and it might be half as much as it was at 80F. How much does that raise oil temps I don't know and it probably doesn't really justify the need to go to a 5W30 but it probably doesn't hurt either.

 

[dnewton3]

Does it matter how hot it is outside?

For most circumstances that would cover 95% or more of our collective operations? No. That is presuming the following:
"normal" (non-racing or stupid-extreme abuse) applications, with liquid cooled equipment, using spec'd fluids, and where the equipment is in good mechanical condition with proper filtration ...


You don't "need" 5w30 in the southeast if your vehicle is spec'd for 5w-20; your dealer if full of phooey. I'd ask him to "prove" his claim with UOA and teardown results, and not rhetoric and hype. Just for fun, ask the dealer where the supposed "cut-off" is for us northern folks? Is it TN, KY, IN? Just where does 5w-20 become "OK" to use in the dead heat of summer? After all, it can get 100 deg here in central IN at least a few times a summer. I've been in SD where it was 101 deg F in summer. How much "hotter" does he think you get in the southeast that we don't see? Perhaps he means 5w-20 is only OK for the Canadians?

It won't hurt, or help, to run 5w30 any more than 5w-20 where you're at. Small grade changes that are out of spec typically don't manifest themselves with any differnt results. If you're spec'd for 5w-20, and you try 20w-50 racing oil, I would expect some issues to develop. But not moving from 5w-20 to 5w30. Same goes for the silly debate of 5w30 versus 10w30. The small nuances just don't grow into big wear issues.

I have been using, and currently run, HDEO 10w30 in my Dmax truck. The spec's call for 15w40 as "preferred" and 10w30 as acceptable alternative. My UOAs came back great, but not any better than those that choose 15w40. I don't lose or gain anything. I just use it because I want a bit quicker start-up cranking in the cold of winter; matters greatly to a diesel, not so much to a gasser. My point is that the small grade shift I choose really does not make any wear difference. And since your two choices are 5w-20 or 5w30, cold starts mean nothing. Get the point?

Want proof for yourself? Run a few UOA/OCI cycles with 5w30, then 5w-20. Not just one of each, but several of each. You'll likely find little (if any) statistical difference in the wear.

 

[dparm]

IMO the ambient temp isn't a big factor. If it was, we'd see car companies listing crazy oil recommendations...especially for people who live in places like Death Valley or whatever. Honda still specs 5w20 for plenty of cars that see ambient temps over 100 while sitting in traffic with the AC on, for example.

 

[gfh77665]

Originally Posted By: dparm
IMO the ambient temp isn't a big factor. If it was, we'd see car companies listing crazy oil recommendations...especially for people who live in places like Death Valley or whatever. Honda still specs 5w20 for plenty of cars that see ambient temps over 100 while sitting in traffic with the AC on, for example.


When are people ever going to understand? Honda "specs" 5-20 FOR U.S. CAFE STANDARDS, period. Everywhere esle around the globe, the exact same Honda engines calls for thicker oils. Please understand this, everyone!!!

 

[Fallguy]

Originally Posted By: gfh77665
Originally Posted By: dparm
IMO the ambient temp isn't a big factor. If it was, we'd see car companies listing crazy oil recommendations...especially for people who live in places like Death Valley or whatever. Honda still specs 5w20 for plenty of cars that see ambient temps over 100 while sitting in traffic with the AC on, for example.


When are people ever going to understand? Honda "specs" 5-20 FOR U.S. CAFE STANDARDS, period. Everywhere esle around the globe, the exact same Honda engines calls for thicker oils. Please understand this, everyone!!!


Now thats quality info! Suggest anyone with this vehicle investigate further. US specs are geared first and foremost for mpg, emmissions & cat protection, not so much longevity of engine. If speced in other countries for xW30 or something of the sort there is evidence.

 

[HTSS_TR]

Honda has no problems meeting CAFE with thicker xW30, their engines reliability and overall reputations is indisputable. They don't need to spec thinner oil to get another 0.5-1.0 MPG on the EPA tests. If any test showed a premature engine wear with xW20, they would not recommend it.

 

[d00df00d]

Originally Posted By: gfh77665
When are people ever going to understand? Honda "specs" 5-20 FOR U.S. CAFE STANDARDS, period. Everywhere esle around the globe, the exact same Honda engines calls for thicker oils. Please understand this, everyone!!!

And this is a bad thing because...?

 

[chubbs1]

Originally Posted By: d00df00d
Originally Posted By: gfh77665
When are people ever going to understand? Honda "specs" 5-20 FOR U.S. CAFE STANDARDS, period. Everywhere esle around the globe, the exact same Honda engines calls for thicker oils. Please understand this, everyone!!!

And this is a bad thing because...?


I think he is trying to say it doesn't matter one bit if you use 5w20,5w30. I use 5w30 in my Accord and it runs great and gets as good as mileage with either. I would love to see what Honda recommends for their Accords in say, Australia? Does anyone know?

 

[gfh77665]

Originally Posted By: HTSS_TR
Honda has no problems meeting CAFE with thicker xW30, their engines reliability and overall reputations is indisputable. They don't need to spec thinner oil to get another 0.5-1.0 MPG on the EPA tests.


OK, then give us any plausible reason why Honda uses 5-30 around the globe, with the glaring exception of the US. Why? Tell us why?

It IS about CAFE!

 

[kr_bitog]

Originally Posted By: rshunter
The real question is whether GM and Toyota ever expected the vehicle to be sold and/or used south of the Mason-Dixon line when they made the decision to recommend 5W-20. I'm going to take a wild guess and say "YES".


Actually last time Toyota TSB stated that 20-weight should not be used for track or very demanding usage in hot climate, but unfortunately I lost the link.

 

[ChuckBerry]

Originally Posted By: gfh77665
OK, then give us any plausible reason why Honda uses 5-30 around the globe, with the glaring exception of the US. Why? Tell us why?


Possibly because they feel that non U. S. consumers are not ready to accept thinner oils because of perceived lack of protection from 20 weight oils. Possibly because U. S. and Canadian refineries are set up to produce 20 weight oils in sufficient quantities for passenger car use and the rest of the world is not.