Why not use straight-weight oils when temperatures are high? When ambient air temperatures never dip below 65F (say for an entire summer around these parts), is there really a need for the "w" rating?
Should I switch to a thicker oil for the summer?
- Thread starter xwhaler
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Because you still need a fast oil flow on start-up, even in the summer. A straight 30 or 40 will be way to thick for quick and efficient early lubrication in an engine with tight-fitting tolerances designed with the assumption that the engine will be pumping a relatively light oil on start.
Again,
A) I agree with the above 10W30 oils have inherent shear stability vis-a-vis 5W30 oils.
This has to do with VI's...others here have vastly superior knowledge of that subject. Feel free to ask them!
B)Again, Do not run a straight SAE30 weight oil unless you absolutely have to. I see no reason for it on todays modern engines.
XW30 oils are arguably the most versatile and universal weight out there.
C) If you really itch for an upgrade?
Go with German Castrol/SLX 0W30 .... very tough, low wear and it is a rather "heavy" 30 weight Cst Viscosity wise.
A) I agree with the above 10W30 oils have inherent shear stability vis-a-vis 5W30 oils.
This has to do with VI's...others here have vastly superior knowledge of that subject. Feel free to ask them!
B)Again, Do not run a straight SAE30 weight oil unless you absolutely have to. I see no reason for it on todays modern engines.
XW30 oils are arguably the most versatile and universal weight out there.
C) If you really itch for an upgrade?
Go with German Castrol/SLX 0W30 .... very tough, low wear and it is a rather "heavy" 30 weight Cst Viscosity wise.
I grew up in Durham, so despite having left years ago, I'm pretty well familiar with your climate. I don't see a need to go thicker up there. I do wonder about this issue where I live now (gulf coast Florida), and have used 10w30 during the summer a couple times on an experimental basis. Of course, its not uncommon (maybe I should say it's common) to have road surface temps will in excess of 100F all through the summer down here. I'm considering trying the new Amsoil 5W-40 this summer to see how it does (I drive a 2003 V-6 Carmy, and of course, Toyota says 5w30 at all times). If I still lived up there, I wouldn't be.
I don't use straight viscosity oils either, although I wouldn't be the least bit concerned about using a straight 30 weight someplace it didn't get below 65F. But not for the reason you give.
I refer you to http://www.geocities.com/CapeCanaveral/3655/VI.html
For viscosity calculations and mobils data sheets for Delvac 30 weight and 10w30 weight.
The straight 30 weight has the same viscosity at 65F as the 10w30 does at 55F.
If you are going to be consistant, then you need to also say that 10w30 is too thick at 55F.
This isn't directed at you personally, but one of the big problems with posts on this board is that so many people blindly make recommendations for certain SAE "viscosities" without giving any consideration to what the actual viscosity of the oil is in the engine in cSt under the conditions being discussed.
I doubt that there is a person on this board (well, maybe a couple
[ April 09, 2004, 01:20 PM: Message edited by: XS650 ]
I know yall have heard stuff like this a thousand times but I'm going to throw this in anyway... There are two vehicles in my family that used straight cheap-o 30wt and Detuch filters for their entire existence. 1972 Monte Carlo 350cuin made it to 295K before complete rebuild. 1987 Suburban also 350cuin is still going strong at 350K, burns 1/2qt per 3000 miles. The Monte pulled so many trailers the ball has no chrome and is deeply gouged, the rear finally went at 300K. The Suburban has been through 3 transmissions and 1 rear end (spectacular failure) but the valve covers have NEVER been off the engine (most maintenance free vehicle we've ever had). This just re-enforces my feelings that good consistent OCI's are the key to engine longetivity. The Monte is a rubber burning hangar queen now w/440K, and the Suburban was sold to a family friend but its still running strong. Maybe striaght 30 isn't so bad, at least in my climate.
No worrys, I don't take your comments as a personal attack at all. The facts are the facts, and I'm fine with everyone who tries to sort them out in good faith. The others I really don't care about... As a counterpoint, consider this, in the Amsoil context. I'm not worried about any Amsoil puffery here, since I'm presenting their own numbers against one another. At 40C (about 100F) their PAO 10w30 has a vis of about 70cSt. On the other hand, the Straight 30 has a vis of about 85 cSt. At 100C, they're about the same, 11.5 and 11.9, pretty much reflecting the difference between multi and straight oils. I'd love to see a set of datapoints for a lower temp, say 0C, but I'll assume (and it's just an assumption) that they continue to diverge as it gets colder (the pour pts are -54, multi and -36 strt, decent either way). I frankly don't know the point at which the difference becomes critical, but I imagine it varies from engine to engine. No, straight 30 isn't engine poison, but even in the summer in a hot climate, a lot of morning starts are going to happen at temps below 65F, so this really may be a problem. I do know that we won't be making that determination in my engine, however. . .quote:
Originally posted by XS650:
I don't use straight viscosity oils either, although I wouldn't be the least bit concerned about using a straight 30 weight someplace it didn't get below 65F. But not for the reason you give.
I refer you to http://www.geocities.com/CapeCanaveral/3655/VI.html
For viscosity calculations and mobils data sheets for Delvac 30 weight and 10w30 weight.
The straight 30 weight has the same viscosity at 65F as the 10w30 does at 55F.
If you are going to be consistant, then you need to also say that 10w30 is too thick at 55F.
This isn't directed at you personally, but one of the big problems with posts on this board is that so many people blindly make recommendations for certain SAE "viscosities" without giving any consideration to what the actual viscosity of the oil is in the engine in cSt under the conditions being discussed.
I doubt that there is a person on this board (well, maybe a couple) who couldn't make a rational comparison of true oil viscosities at any temperature between about 32F and 150F for a given oil based on spec sheets. But for some reason, few bother.
[ April 09, 2004, 03:47 PM: Message edited by: ekpolk ]
The amsoil 30 and 10w30 viscosities are close to the Mobil Delvac dino viscosities I used.
You chould be able to get a resonable view of how they diverge down to 0C or so using the calculator at:
http://www.geocities.com/CapeCanaveral/3655/VI.html
There is obviously some limit to how far you can extrapolate from 40C and 100C data points, but 0C is probably OK.
Before 10w30 oils were sufficiently ruggedized, I used straight 30 weight year round for years in mild winter areas of Northern California without a problem. I haven't in over 20 years because there is no longer any reason to.
I'd recommmend running a 10w30 or 5w-40, CI-4 rated diesel oil over the summer - mainly to get some additional protection from corrosion caused by salt spray ....The Rotella T, 5w-40 at Walmart is a very good oil for the price - about $13.00/gallon - and probably the easiest oil to find.
The Mobil 1, 5w-40 would be even better, but more expensive.
Tooslick
www.lubedealer.com/Dixie_Synthetics
The Mobil 1, 5w-40 would be even better, but more expensive.
Tooslick
www.lubedealer.com/Dixie_Synthetics
My wife's Explorer ran on Motorcraft 5W30 with 5K changes as long as we had it, 175,500 trouble free miles.
In any event, Summertime temps are much warmer in North Carolina (high 80's and into the 90's) and we experienced no problems with this oil. This was a '96 model with the older 4.0 though. Car never consumed oil though it did turn quite dark by the 5k mark when it was to be changed. The car saw mostly hwy/interstate miles, so I was satisfied with 5K changes.
My main concern with this car was with the transmission (rumors of the Exploder transmission). So I had a transmission cooler installed and had the fluid flushed every 30,000. Transmission still ran trouble free when we traded last month.
In any event, Summertime temps are much warmer in North Carolina (high 80's and into the 90's) and we experienced no problems with this oil. This was a '96 model with the older 4.0 though. Car never consumed oil though it did turn quite dark by the 5k mark when it was to be changed. The car saw mostly hwy/interstate miles, so I was satisfied with 5K changes.
My main concern with this car was with the transmission (rumors of the Exploder transmission). So I had a transmission cooler installed and had the fluid flushed every 30,000. Transmission still ran trouble free when we traded last month.
I had an Explorer. It got Valvoline 5w30 and ran great till 135000, when it was sold. my mom has has the 4.0 OHC engine. It got Mobil 1 10w30 from 69K-135K with 10K change intervals, then my father saw the '5w30 recommended', so it was switched to Mobil 1 5w30. For the last 5000 it has had Castrol High Mileage 5w30 with 3K change intervals. It currently has around 152K. Never has it used oil. That engine seems like a very strong engine! It most likely won't hurt a thing to use 10w30 in the summer and 5w30 in the winter, or always 5w30. It's a good engine!
We have a Chevron distribution dealer, I haven't seen the Delo400 10-30 anywhere else...Walmart etc. Wish Walmart would carry this weight, I think it would be a big seller.
What I DON'T like about this board: Guys in Hawaii talking to guys in Nashville about cold climate. You know, it's not too late to snail-mail you guys some snow. Packed in dry ice and COD, mind you
Yours 1200 miles due North of Dallas,
Rob
I think you're higher up than that. I'm 300 miles from Canada and I'm in MN.
Delo is a Chevron product, as in Chevron 15w40 Delo. But I am using Chevron's 10w30 now, as it was not formulated for diesel.(DELO).
I have used Chevron's 10w-40 and it also not called a Delo.
[ April 18, 2004, 10:56 PM: Message edited by: Lubricious ]
No offense rob-the-oil-nut...no what cold weather is lived in Wash DC...Like I said it gets tough in cold weather, it's gotta be a pain on cold mornings...
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