Here we go again. A revived old oil thread that is just like all other oil threads. No conclusion or changing of opinions. Understandable why a moderator of another auto forum banned oil threads.
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You make it sound like someone is forcing you to read them or youāre being personally charged for every post made here. If you donāt like them, just donāt read them. Quit trying to force your will/desire on everyone elseā¦
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Well, here is the update. The 0W40 has been used in all the vehicles requesting 5W30 from the factory. It is the same price and appears to be a better oil. Yes, I am fully aware of how Wal-Mart forces their vendors to sell a lower quality version of something at their stores at a cheap price but this oil meets all the same specs as it does anywhere else for a higher price. I hate going to Wal-Mart and this is one of the few reasons I still go there from time to time which has been once a month or so lately. That is a whole different story about my Wal-Mart experience though.
Here are my experiencesā¦ Nothing bad has happened and overall I would say it is good. The first change got dirty REALLY quick so I made sure not to push it beyond 3000 miles, then I went to 5000 miles. Obviously this stuff dissolves crud that has accumulated over time.
Besides this, the intermittent cold start lifter ticks have gone away. Yes, the oil serves as a hydraulic fluid so viscosity is important. One of the issues with Geos is that they are known for burning valves. That is the weak link on these little engines. Deposits formed burned oil form hotspots on the valves, causing them to warp and burn. Failed valves look like someone took a bit our of them or someone cut a pizza slice out of them. The other reason this happens is someone used too thick of an oil, especially in a colder climate. The lifters overpump and the valves never quite close while the engine and oil is cold, causing them to burn. It seems you want to stay with a 5WXX or thinner oil in these engines unless you live in part of the country where it remains pretty hot year round. I say why chance it as the thinner stuff works fine. These engines were designed before synthetic oils were common and oils have come a long way in 30+ years. I see people using 0W20 to try to save fuel and all the way up to Rotella T6 5W40 to prevent wear. I could hear the cam journals buzzing on cold start below 40 F so think this one is too thick for these engines. The 0W40 is just right if you ask me. It will start easily well below zero with no cam journal buzzing and can hold up in higher temp situations. If it is good enough for a Mercedes Benz AMG, it is good enough for a GEO!
Now a new car has arrived (2015 Mitsubishi Mirage) and it requires 0W20 synthetic in the USA. The interesting thing is that this engine is used all around the world and it calls for up to 10W40 in other countries but with a much shorter change interval on the conventional oil that is allowed. It uses solid lifters but is DOHC with variable valve timing.
This same 0W40 oil has come up on the Mirage forum as well. A couple guys are sending in their oil analysis on the oil soon. I will consider changing to it if there are significantly lower wear numbers. Otherwise I will stick with the 0W20 as called for in the manual and avoid the mileage penalty.
According to whom? Knowing who is making this decision is kind of important.
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Regarding oil weights, a 3800 series II from 1995 has 10w30 stamped on the oil fill cap. My car has a 3800 series II, but was made in 2005 and has 5w30 stamped on the oil fill cap. I donāt think a difference of 5 cold, 10 hot in oil weight will make a hill of beans difference. Just my opinion. Just donāt go crazy and pour 20w50 in there.
So, you donāt think the manufacturer has made any changes whatsoever in 10 years of manufacturing the engine? No change in manufacturing technologies that might affect tolerances? No change in casting technology? Materials? Valvetrain? No change in the way the engine handles its lubricants? And you donāt think oils have changed?
The two engines may well have significant differences. Designs are constantly tweaked. I wouldnāt assume that theyāre exactly the same engine through and through.
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I agree. I think a lot of the thinner oils lately are all being used in the same engines as before but the oil is better and can protect better. Now they may make some adjustments to the bearing clearances but with the Mitsubishi engine I mention, there is a HUGE variation on oil viscosity for the same engine. The thinner oils are specified here to meet EPA standards.
Everything I have read on that 0W40 tells me it isnāt very far off from being a 5W30. This is to keep the additional anti-wear additives required by the European makes. These have been removed from US oils because they can foul your emissions systems components such as the catalytic converter if oil is burned. All engines burn SOME oil of course but it may be too little to notice between changes. Anyway, you basically get a slightly thicker oil with a better additive package for the same or less money so why not??? The European standards are a lot more stringent than ours.
I am not going way out of grade on the oil viscosity. It is a relative minor variation and doubt it will hurt anything besides maybe some fuel economy numbers. These engines allowed for 10W30 according to the manual in the early years. This was changed because the 10WXX oils were causing valve burning in colder climates. The hydraulic lifters were also re-designed but they no longer specified 10W30.
Again, we will be arguing about oil when the body of the car is destroyed by rust and the engine is scrapped but still running strong.
I am sure there are differences between the engines but there are times where the same engine is specified with a lower viscosity oil to improve EPA standards just a tad. This is a really cheap and easy way to get 1-2 MPG gain so it is the lazy way to do it. A buddy who is into the Ford 4.6L indicated that the same engine calls for 5W30 in one year and 5W20 the next. There is nothing different about the engine but it has a bit better EPA rating.
I would never consider 10W40 or 20W50 in such an engine though.
I find it funny that some of my mowers call for 15W50 or 20W50 oil as their hydraulic fluid. One even calls for 5W50 which is quite hard to find. I found some on clearance and bought everyone for about a $1. This was normally quite pricey.
I have no doubt of that. But I wouldnāt assume that two engines ten years apart are exactly the same and use that as a basis to use other than a recommended lubricant. Changes are constantly made to all aspects of a car design, including engines. It isnāt uncommon for a shop to get a wrong part in from the parts store because there was some change to the part or engine. Same make, same year, same model, same engineā¦ but the partās been modified.
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I certainly know there are differences, even within model years! Ask me how I knowā¦ Had I known what I was getting into with a 1997 F-250 Light Duty, I would have RUN from this truck! Everything is good now that I have replaced everything but this thing is the biggest mismatch of parts I have ever seen. It got to the point where I didnāt even bother to have them lookup parts. I just removed the old part and took it in and asked for that part. They would be like āThat is from a 1998ā or āThat is from a 1996ā. They would get it wrong even after I pulled out my insurance card with a VIN number.
By the way, I believe that truck has 5W20 or 5W30 on the oil fill cap.
Probably 5W30, I donāt think anyone was using any flavor of 20 weight in 97. But I could be way off base again.
That is daily practice here in Mexico. People mostly think you have to use 20W-50 or you will ruin your motor. As a result, many stores donāt even stock anything else. Once AutoZone in Tehuacan even had only 20W-50.
When I drive to the border I bring back Mobil-1 EP in 5 quart bottles, enough to last until next trip. The problem is my 2009 Sienna takes more than 5 quarts.
A comment on the constant whining about opening old postings. First, admin allows it so obviously approves it.
Second, cars being what they are, anything that was relevant in 2005 is probably still relevant. If a 2005 Chevrolet had a problem in 2005, 2005 Chevrolets probably still have that problem today.
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Iām comfortable assuming that a GM ā3800 series IIā is a ā3800 series IIā. Yes.
If anyone researches and finds any significant differences, I will be the first to call myself a knucklehead. But I donāt think youāll find any changes.
FWIW, I use 5w30 anyway. I do know that the egr valve off that Pontiac Bonneville fits my Buick, and so far, relieves me of the CEL.
But this is GM here. Their stuff is (was) very interchangeable. Other makes, not so much.
I found it interesting the Bonnie called for 10w30. The Silverado with the 350 of the same era called for 5w30. I canāt explain that. For certain, those throttle body 350ās didnāt have ātighter tolerancesā. So I dunno.
I might dump 20W50 into an old worn out oil burner without hydraulic lifters or variable valve timing. Otherwise this sounds like trouble.
GM is probably the best about having interchangeable parts. I donāt know about the last 10 years or so but the older models were certainly good about that. They were the masters of badge engineering for a while. Again, you have the same basic parts but they call for a different oil viscosity. Strangeā¦
Although engines have changed, oils have also changed. Thinner oils protect better and there is no way you could have protected and engine with 0W(anything) in the old days. Now it is quite common. A 0W40 might be about as close to a universal oil as you can get.
I run that Rotella T6 5W40 in all of my mowers and most of them originally called for 10W30. I have to say those engines seem to hold up better since that change. I do tend to run them quite hard and show them no mercy and the oil seems to hold up quite well. I am always amazed that it doesnāt look more broken down when I change it each season and I put a lot of hours of hard use on those engines. This is a full synthetic which helps withstand the high heat and stresses of an air-cooled engine.