Oil Question

HarryD · 01-07-2011, 09:12 PM

Yes, I know the moderators will move this but for a few minutes, maybe someone can help me out.

My Windstar calls for 5W-30 oil but I got a good deal on 10W-30. For the life of me, I cannot figure out the downside to going to the oil that is slightly heavier when cold. I figure the requirement is to meet some EPA Mandate for fuel efficiency.

To my way of thinking, once either of these oils is at operating temperature, they are the same weight. As long as I am not operating my car in some place that regularly sees temerpatures below 10F, the car will crank over fine and run and warm up normally.

Anyone have any thoughts?

BTW, the Windstar is used to haul my 911 parts and my wonderful wife uses it to bring me to and from my 911 wrench when needed. Ah-ha! 911 content.

tcar · 01-07-2011, 09:16 PM

Should be fine in Portland.

North Dakota, no.

HarryD · 01-07-2011, 09:49 PM

tcar:

That's what I think but sometimes I can be too smart for my own good.

RoninLB · 01-07-2011, 10:49 PM

i read that the clearances in these new engines are so tight that a heavier than required oil won't lube it properly

might be something to look into

Neel · 01-07-2011, 11:03 PM

You should use the factory recommended weight in any street engine, due to aformentioned tighter clearances, and other things such as oil fed cam chain tensioners, variable cam timing etc..

Steve@Rennsport · 01-08-2011, 12:05 AM

Quote:

Originally Posted by HarryD

tcar:

That's what I think but sometimes I can be too smart for my own good.

Boy, howdy!!

HarryD · 01-08-2011, 12:14 AM

Quote:

Originally Posted by RoninLB

i read that the clearances in these new engines are so tight that a heavier than required oil won't lube it properly

might be something to look into

At first glance this argument makes sense but with a multigrade oil, the weight of the oil is the higher number when warmed up and this would also be the time when you would expect the tolerances to be at their closest.

In my case (1996 ford Windstar with 110,000 miles, I suspect things have lossened a bit and for cold starting, the difference between 5W and 10W does not matter in Portland, Oregon. Do note that I did not increase the viscocity of the hot oil (30W in either case).

dshepp806 · dshepp806's Garage

I'd stay with the manufacturer's recc's....5W.

Doyle

Oh Haha · 01-08-2011, 03:50 AM

With over 100k I wouldn't sweat it. I use 10W30 in the Maaaaazda.

If you were in an extreme cold climate I would say otherwise.

JerP · JerP's Garage

+1 to Wayne and tcar

ljowdy · 01-08-2011, 06:59 AM

As explained to me by Ford and GM engineers.. And the way I fugure it, they didn't spend a lot of money and time deciding on the grade of oil if it wasn't important.

I'm paraphrasing here but this is basically what engineers from both companies said:

If the engine calls for a specific grade of oil, then use what's recommended. Oil passages are much smaller in diameter and heavier grade oil, on start up, won't flow as rapicly as lighter oil. Because the cooling systems are far superior than they used to be, the heavier oil isn't needed when outside temperatures are high. The lighter grade of oil has been tested in both hot and cold climates and has proven it self to be superior.

tcar · 01-09-2011, 10:32 AM

Quote:

Originally Posted by HarryD

tcar:

That's what I think but sometimes I can be too smart for my own good.

I AM too smart but it is for my own good...

bklyn · 01-09-2011, 10:38 AM

I still want to know why we should not use Shell Rotella which was the orig. fill by Porsche?

Danny_Ocean · 01-09-2011, 10:42 AM

Quote:

Originally Posted by bklyn

I still want to know why we should not use Shell Rotella which was the orig. fill by Porsche?

Formulation has changed. Used to have adequate levels of zinc/phospate, but now does not (new diesel motors have catalytic converters of sort). I have a shelf full of the "old" formula if you wanna buy it (I'm just south of you in Broward).

bklyn · 01-09-2011, 10:45 AM

Oh, I was not aware they changed it. Buy the way I work in Broward for the Sheriff's Office.

Danny_Ocean · 01-09-2011, 10:49 AM

Quote:

Originally Posted by bklyn

Buy the way I work in Broward for the Sheriff's Office.

At a detention center or at HQ? (Or are you one of those pesky code-enforcement officers?)...

Targalid · 01-09-2011, 12:28 PM

It has to do with properly inflating the hydraulic lifters. Too heavy an oil and the newer lifters do not fill and you get a flat cam. In hot summer weather it does not seem to matter that much but now is another story.

HarryD · 01-09-2011, 02:11 PM

Quote:

Originally Posted by Targalid

It has to do with properly inflating the hydraulic lifters. Too heavy an oil and the newer lifters do not fill and you get a flat cam. In hot summer weather it does not seem to matter that much but now is another story.

So, what you are telling me is that if the lifters do not fill immediately upon startup (with the ever so slightly less viscous 5W oil), they will not fill later with the heavier oil?

Targalid · 01-09-2011, 08:00 PM

I have heard the difference on a couple of motors. It takes a while for the oil to warm up. I have not disassembled the lifters to see what the exact reason is because I have not needed to do so yet. The older hydraulic lifters were not so picky. I was warned specifically on the Geo engines that a common way to ruin them was to use 10W30 instead of 5W30. I don't know the Windstar but I have heard the difference thicker oil makes on Chevy motors with hydraulic lifters. It sounds like cam slap on loosely adjusted valves.