Auto manufacturers viscosity recommendations?

[ron in sc]

Should auto owner follow auto manufacturers viscosity recommendations?

After reading what my owners manual for 09 Toyota Avalon says about oil viscosity I’m not certain their recommendations apply to me or to the weather we have where I live. I'm thinking too they are not requirements but just recommendations. In other words not using the recommended viscosity would not mean no warranty coverage.

Here’s what owner’s manual says about Recommended viscosity:
SAE 5W-30 is the best choice for good fuel economy, and good starting in cold weather.
If SAE 5W-30 oil is not available, SAE 10W 30 oil may be used. However, it should be replaced with SAE 5W-30 oil at the next oil change.
They do not define cold weather. So what is it? To me it's cold when it gets into the 40s.

Manufacturers stated goals of good fuel economy and good starting in cold weather are not my top priorities. Of course I don’t want an oil that is so viscous that it will not lubricate properly at startup.

I’ve been running Mobil 1 15W-50 in two 1992 Mercedes cars with 6 cylinders for 10 years, another 1999 Mercedes SUV 6 cylinder since new and a 1997 Porsche 6 cylinder also with Mobil 1 15W-50. I’m not using the viscosity recommended by the manufacturers except maybe the Porsche. Now though I think Porsche as well as Mercedes are recommending 0W-40 for all their vehicles; at least for models made after 1999.

I’m having a hard time trying to figure out what viscosity to use when my primary goal is engine health and long life. In the old days you just used a chart that let you pick a viscosity based on lowest and highest ambient temperatures you expect to encounter. Whatever happened to that method?

 

[demarpaint]

The car was sold in North America, it appears they are suggesting 5W30 for it, for use in North America. Not to get into a big debate, I'd use 5W30 and call it a day, unless they back spec'd it for something else. Besides you have a warranty to comply with. JMO

 

[bepperb]

Aren't there thousands of Toyotas in junkyards whose engines are perfectly fine (outlived the car), the vast majority of which were run on factory spec motor oil?

Put another way, is there reason to believe that the engine won't hit 500,000 miles running on 5w-30? I wouldn't think so, even under severe duty (for an Avalon). I'm actually surprised it doesn't call for 5w20.

What are you trying to do here? Are you willing to void your warranty based on a the unproven theory your engine is better off with a thicker oil? Many people are, especially around here, but you'd have to provide more details of the situation before you could win me over.

An edit to what happened that manufacturers changed their requirements and don't have a "chart"... well, motor oils have gotten better at both handling high heat and cold weather starting, engine management and cooling systems have improved. Really, on most cars the oil temp is relatively stable regardless of ambient temp.

 

[jldcol]

I think the primary auto manufacturers concern with oil recommendations is to help insure that the engine makes it thru the warranty period, and thus saves them money. Lately the government has pressured things like emissions systems and mileage concerns on top of that. Generally a gasoline engine needs a working 30wt. to last the warranty period, and a 40wt. perhaps for diesels. The cold numbers needed depend on your climate, so will differ more. The warranty and its satisfaction will limit you a lot, afterwards it seems you allready have favorite with some past experience. I will say the stuff from 92 may not be the same stuff now.

 

[ron in sc]

Quote:
What are you trying to do here? Are you willing to void your warranty based on a the unproven theory your engine is better off with a thicker oil? Many people are, especially around here, but you'd have to provide more details of the situation before you could win me over


As far as this warranty business goes using an oil that in not recommended by a manufacturer will not void the warranty. There is a difference between a recommendation and a requirement. The burden is on the manufacturers to prove that the use of the specific oil that was used caused the problem that the auto owner is claiming.

 

[bepperb]

I agree that's how it should go, they shouldn't void your warranty. But if they find out that's what happened, or if they ask for reciepts, it will be a million headaches and runarounds and who knows what... except that it won't be good.

There's a very low possibility you'll have engine problems at all. But if the warranty coverage is important to you it's something to keep in mind. Otherwise, I imagine you'll just get slightly worse gas mileage and theoretically better protecton. For me, it would just be trading one peace of mind (warranty) for another (oil that has worked well for you).

 

[lexus114]

You can quite safely use Mobil-1 0W-30,or PP 5W-30.Or just a good conventional 5W-30 will be fine.I have a 2001 Lexus RX 300,and am currently using the M-1 0W-30,and it runs very nicely on it.

 

[Steve S]

If running syn oil it probably wouldn't really matter because syn oils better cold specs. The 30wt syns would most likey be all the oil the Toy would need.

 

[Colt45ws]

Quote:
Generally a gasoline engine needs a working 30wt. to last the warranty period, and a 40wt. perhaps for diesels.

Millions of Ford, Honda, Toyota and Chrysler vehicles must be on the brink of self destruction then. Im sure we'll hear about it on the news.

 

[Liquid_Turbo]

"SAE 10W 30 oil may be used. However, it should be replaced with SAE 5W-30 oil at the next oil change."

Thats what I don't get. Why must it be replaced at the next change?

 

[lexus114]

their probably looking at cold starting.

 

[demarpaint]

Originally Posted By: ron in sc
Quote:
What are you trying to do here? Are you willing to void your warranty based on a the unproven theory your engine is better off with a thicker oil? Many people are, especially around here, but you'd have to provide more details of the situation before you could win me over


As far as this warranty business goes using an oil that in not recommended by a manufacturer will not void the warranty. There is a difference between a recommendation and a requirement. The burden is on the manufacturers to prove that the use of the specific oil that was used caused the problem that the auto owner is claiming.


I respectfully disagree. If an engine blows because of an oil related issue the company might just look for a way out. They will certainly send the oil out for an analysis. If you use the suggested oil, 5W30 in your case, and follow the rules, suggested OCI's, and proof that you did it by the book, you have a fighting chance. If they see you used a 15W50 or some other oil you'll be the one trying to prove the oil didn't ruin the car, while it sits on the dealers lot waiting for things to be sorted out. A headache that I certainly wouldn't want. But you are certainly free to do whatever you decide to do, hopefully w/o issue. JMO

 

[Bryanccfshr]

Originally Posted By: demarpaint
Originally Posted By: ron in sc
Quote:
What are you trying to do here? Are you willing to void your warranty based on a the unproven theory your engine is better off with a thicker oil? Many people are, especially around here, but you'd have to provide more details of the situation before you could win me over


As far as this warranty business goes using an oil that in not recommended by a manufacturer will not void the warranty. There is a difference between a recommendation and a requirement. The burden is on the manufacturers to prove that the use of the specific oil that was used caused the problem that the auto owner is claiming.


I respectfully disagree. If an engine blows because of an oil related issue the company might just look for a way out. They will certainly send the oil out for an analysis. If you use the suggested oil, 5W30 in your case, and follow the rules, suggested OCI's, and proof that you did it by the book, you have a fighting chance. If they see you used a 15W50 or some other oil you'll be the one trying to prove the oil didn't ruin the car, while it sits on the dealers lot waiting for things to be sorted out. A headache that I certainly wouldn't want. But you are certainly free to do whatever you decide to do, hopefully w/o issue. JMO


+1 If you are willing to go outside of the manufacturers specification you should be willing to pay for any repairs down the road. THe Magnusson-Moss Act will not protect you from terrible inconvenience and possible loss of use of the vehicle and possibly losing the case anyway.

If you really want to run a 15w50 oil then find a vehicle that specs it and buy that vehicle so you can run your favorite oil. (truely putting the cart before the horse here but whatever.

 

[Liquid_Turbo]

Originally Posted By: ron in sc
Should auto owner follow auto manufacturers viscosity recommendations?


Sure, they built and designed the engine, didn't they?

 

[Liquid_Turbo]

"SAE 5W-30 is the best choice for good fuel economy, and good starting in cold weather.
If SAE 5W-30 oil is not available, SAE 10W 30 oil may be used. However, it should be replaced with SAE 5W-30 oil at the next oil change."

Cold weather = anything below 10C.

Using common sense, you should be able to deduce what Toyota is trying to tell you.

First choice: 5w30.
Second choice: 10w30.

To me, the only confusion is replacing 5w30 after you use 10w30. But notice how they say "should". Makes me deduce that 10w30 is suitable to use.

What is so wrong w/ 5w30? It's time proven to be a great compromise.. great protection with good economy. Seems like 5w20 is starting to fill that niche now.

This is assuming the Avalon isn't going to be boosted or track driven of course.

 

[3Toyotas]

Originally Posted By: Steve S
If running syn oil it probably wouldn't really matter because syn oils better cold specs. The 30wt syns would most likey be all the oil the Toy would need.


Agreed.

With my experience on Toyota vehicles (14 since 88), there is no need to go any thicker than a 30w. Most all toyota motors are very easy on oil, and can go hundreds of thousands of miles on a simple 30w dino.

If it makes you feel better, run the 10w30 in the summer, and 5w30 in the winter. But if it were mine, i'd use a full synthetic 5w30 year round and not lose any sleep over it.

 

[RTexasF]

The 3.5 V6 is also spec'd for 5W20! I'll be running 5W20 in mine the first oil change. So now you have three that are legit 5W20, 5W30, or 10W30. Pick one and get on with it. There is no reason to go to a heavier oil than those prescribed by the maker.

 

[TallPaul]

Originally Posted By: Liquid_Turbo
Originally Posted By: ron in sc
Should auto owner follow auto manufacturers viscosity recommendations?


Sure, they built and designed the engine, didn't they?
But the owner's manual recommendation is not just what the engineers recommended, but also is colored by CAFE considerations which have nothing to do with what is best for the engine.

 

[StevieC]

I always like to go by the technical service manual where it shows the chart of temperatures versus the chart of oil viscosity that are acceptable to use... This to me is the best way to gauge your oil viscosity choice accurately!

 

[Big Jim]

Originally Posted By: jldcol
I think the primary auto manufacturers concern with oil recommendations is to help insure that the engine makes it thru the warranty period, and thus saves them money. Lately the government has pressured things like emissions systems and mileage concerns on top of that. Generally a gasoline engine needs a working 30wt. to last the warranty period, and a 40wt. perhaps for diesels. The cold numbers needed depend on your climate, so will differ more. The warranty and its satisfaction will limit you a lot, afterwards it seems you allready have favorite with some past experience. I will say the stuff from 92 may not be the same stuff now.


If this were true there would be a huge percentage of cars with worn out engines just past warranty. This just isn't so.