0w20 vs 5w20 vs 10w30 Engine Oil Viscosity

[dirt40]

Originally Posted by zombiewoof

Oil selection for vehicles is the subject of endless debate. Manufacturers test and certify oils for use in their engines. Using the recommended oil is a safe bet and does not void the warranty. That being said, the EPA requirements for emissions and the CAFE standards for fuel economy drive oil selection to a very large extent. Engine protection may be compromised under certain conditions but this doesn’t matter from a statistical standpoint. The automotive companies understand this and accept the very small warranty issues that may arise from using light weight oils. Remember, CAFE and emission issues can easily cost them multi millions of dollars.

My 2008 Ridgeline specified 5W-30 oil. My 2012 Ridgeline specified 0W-20. What changed? There were slight mods to the 2012 drivetrain to address the weak acceleration at higher speeds. This reduced the fuel mileage ever so slightly. Solution was to make the oil thinner to gain the mileage back. The last several generations of Corvettes require thicker oil for track use. Why? Because the thin EPA required oil does not protect the engine at high loads. My 2012 Jeep Wrangler specifies 5W-30 oil. When off-roading that engine works hard putting lots of stress on internal components. I am not comfortable with this so I use 10W-30 for increased protection. I no longer buy different viscosity oils for my two vehicles. I use 10W-30 in both and accept the minuscule reduction in fuel mileage and (maybe) some minuscule extra extra wear at startup for better engine protection at high ambient temperatures and high loads. Very much a personal decision.

So in your jeep the 10w30 protects better than a 5w30? Are you losing oil pressure when you're off roading and the oil is hot?

[zombiewoof]

Can’t say about any oil pressure loss since there is no oil pressure gauge on a Wrangler. The valve train is noisier with 5W-30 versus 10W-30.

[wagonmaster2]

Originally Posted by EdInArk

I have a similar situation -- 0w20 for the car, 5w30 for my truck, 5w20 for the RV. At least both motorcycles use 10w40. I can remember when a straight 30 weight was good for everything.

That's remembering back a long time. Me too. 30W in the summer, 20W in the winter.
I also remember the detergent oil controversey. Detergent oil will just clean and carry all that engine carbon crud and contaminents around to all the working components rather than letting it settle to the bottom of the engine pan. Used to clean engine parts for Dad during overhauls at his shop and I could dig stuff off the bottom of engine pans with a putty knife, like mud.

[wagonmaster2]

Originally Posted by zombiewoof

Oil selection for vehicles is the subject of endless debate. Manufacturers test and certify oils for use in their engines. Using the recommended oil is a safe bet and does not void the warranty. That being said, the EPA requirements for emissions and the CAFE standards for fuel economy drive oil selection to a very large extent. Engine protection may be compromised under certain conditions but this doesn’t matter from a statistical standpoint. The automotive companies understand this and accept the very small warranty issues that may arise from using light weight oils. Remember, CAFE and emission issues can easily cost them multi millions of dollars.

My 2008 Ridgeline specified 5W-30 oil. My 2012 Ridgeline specified 0W-20. What changed? There were slight mods to the 2012 drivetrain to address the weak acceleration at higher speeds. This reduced the fuel mileage ever so slightly. Solution was to make the oil thinner to gain the mileage back. The last several generations of Corvettes require thicker oil for track use. Why? Because the thin EPA required oil does not protect the engine at high loads. My 2012 Jeep Wrangler specifies 5W-30 oil. When off-roading that engine works hard putting lots of stress on internal components. I am not comfortable with this so I use 10W-30 for increased protection. I no longer buy different viscosity oils for my two vehicles. I use 10W-30 in both and accept the minuscule reduction in fuel mileage and (maybe) some minuscule extra extra wear at startup for better engine protection at high ambient temperatures and high loads. Very much a personal decision.

My 2017 Jeep Wrangler specifys 5W20. I can understand the 5W since upon startup my engine hits 1500 RPM almost immediately, which I don't like but cannot do anything about it. With the strain these Jeeps go through hill climbing I think I would agree with the 5W30 better than 5W20. May change to 30 next oil change.
The 0W20 is synthetic, whereas I don't think 5W20 is unless buying synthetic on purpose. Can this be making any difference between years on the Ridgelines. My 2019 calls for 0W20.

[EdInArk]

Originally Posted by wagonmaster2

That's remembering back a long time. Me too. 30W in the summer, 20W in the winter.
I also remember the detergent oil controversey. Detergent oil will just clean and carry all that engine carbon crud and contaminents around to all the working components rather than letting it settle to the bottom of the engine pan. Used to clean engine parts for Dad during overhauls at his shop and I could dig stuff off the bottom of engine pans with a putty knife, like mud.

When we got married my wife had a '63 Chevy II that she'd gotten from her grandmother. I asked her when she'd had the oil changed last, and she hadn't. Her grandmother also didn't know when. So I took it to a buddy's service station, put it on the lift, removed the plug, and nothing came out.

My buddy took a short screwdriver and pushed up through the sludge, and it started draining.

[Gary RVRoamer]

I have a similar sludge story. Got my first car (a 48 Dodge club coupe) from my 82 year old grandfather, who couldn't remember when last it was serviced. The oil filter was a paper cartridge inserted in a metal tank. When I took the tank cover off, the sludge was packed to the top and I had to pry the paper cartridge out with a screw driver. Then scooped out more sludge with a spoon. Back then, there were no multi-viscosity oils, so we used 30 weight in the summer and 20 in the winter. Oil was supposed to be changed every 1000 miles anyway, so we just used what ever was appropriate for the weather. The old Dodge was an SOB to crank when it got below 20 degrees and sometimes I had to jump start the 6v Dodge with a 12v battery to get it to turn over with that 20 or 30 weight oil acting more like glue than lubricant at 0 F.

My next car was a '56 Olds with a spin-on filter and 10W30 oil was available. I thought the modern technology was fabulous!

[wagonmaster2]

My first car when I was 14 was a 1937 Chev, and not even having an oil filter Dad and I installed one of the tank filters with the paper inserts.
Remember the Kendall 2,000 mile oil, really thought we had a great deal now instead of 1,000 miles.

Kind of off the thread subject but enjoy hearing about all the past engine oil experiences.

[Earl II]

So, since we are swapping oil stories, here is mine. We had a new 1994 Volvo 960 sedan that called for 15W-40 weight oil which is commonly used in diesels. I always used synthetic. So almost 30 years later, I see that the Onan/Cummins generators on our rigs call for 15W-40. Try finding it on the rack at any auto parts shop and you will not find it. I searched online and finally found a few places that carry it. As far as our rig, the cap says 5W-20 so that is what I use. No, don't use a Ford filter, use a K&N. Either way, it would be fine.

[SteveJ.]

Originally Posted by Earl II

So, since we are swapping oil stories, here is mine. We had a new 1994 Volvo 960 sedan that called for 15W-40 weight oil which is commonly used in diesels. I always used synthetic. So almost 30 years later, I see that the Onan/Cummins generators on our rigs call for 15W-40. Try finding it on the rack at any auto parts shop and you will not find it. I searched online and finally found a few places that carry it. As far as our rig, the cap says 5W-20 so that is what I use. No, don't use a Ford filter, use a K&N. Either way, it would be fine.

15w40 in synthetic is a bit of a rare bird but it is available in Shell Rotella. I've seen it at Walmart and Rural King in the last month.

[Kraken]

Motor magazine just had an article on oils. They said that engines are changing so fast that the oil companies can't keep up.The new SN Plus rated oil should be out soon or is already out.

[Gary RVRoamer]

I see that the Onan/Cummins generators on our rigs call for 15W-40. Try finding it on the rack at any auto parts shop and you will not find it. I searched online and finally found a few places that carry it.

Shell Rotella T6 is a full synthetic and widely available in the 15W40 used by many diesels. My local Walmart, Advance Auto, Sam's Club, Rural King and O'Reilly's all carry it. Mobile Delvac synthetic is also available at a couple of them.

[Earl II]

Originally Posted by Gary RVRoamer

Shell Rotella T6 is a full synthetic and widely available in the 15W40 used by many diesels. My local Walmart, Advance Auto, Sam's Club, Rural King and O'Reilly's all carry it. Mobile Delvac synthetic is also available at a couple of them.

Not in SoCal.

[Jol]

Originally Posted by Mudfrog

Our 2019 Volkswagen specifies 0W-20 oil. On top of that, it's supposed to be VW508 approved which makes it hard to find. The manual specifically states to use only oil meeting these specs.

We have a 2012 VW yes it is a diesel and have been using 5-30 for years last oil change they went to 0-30 called VWOA and asked is this a fact and yes it is fine to use it as long as it meets the 507-00 VW spec I had enough trouble finding the 5-30 meeting specs. Guess I will have to go on a search again.