Oil grade: 5W20 vs 5W30?

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Rhodius

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I plan to use Mobil 1 with my CX-9. I've always used 5W30 in my X5 (per manual), but from what I read in the CX manual, it's recommending using 5W20.

When I googled, it seemed the newer car (my X5 is only 5 years old, what were they thinking?) these days run on 5W20. I'd hate having to label them separately and since I buy in bulk, I don't like to carry both of them.

Can anyone tell me or point to sites that can explain, can I safely use 5W30 for both cars or should I switch to 5W20 for both cars?

Thanks.
 
I use 5W-30 in all of my cars. 5W-20 is a lame attempt by Ford to get a few tenths extra MPG in the EPA test. No other manufacturer uses 5W-20.
 
Personally, I'd use 30 weight in this case. It is correct. The only reason for 20 weight is to save a few MPG in the long run. I don't think its the best idea, I'd rather the engine be protected. Go with something a touch heavier.
 
5w-20

Using 5w-30 will present no problems.

5w-20 is being driven by the government as much as anyone. There isn't a signficiant difference between 20 and 30. Keep in mind the wording is recommended, not mandatory.

I've seen some really big dust ups over the topic of oil and oil changes on other website to the point of being ridiculous.

Use a good grade of oil with API certification and follow the manufacturers drain intervals. Brand is up to you. I use Mobil 1 myself in my '04 Acura TL and have had no issues. Honda recommends 5w-20 as well for their engines but I've used 5w-30 and not seen any change in mileage. 20 weight synthetic doesn't bother me. Independent testing has shown 5w-20 synthetic holds up just fine. The additive package is the important thing.

I'm going to use the same oil in the CX-9 I use in the TL and follow Mazda's schedule for the change interval.

Ted
 
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Ummm. I'll insert my opinion here, too. I would use the 5W20. Reason being is if there is ever a failure due to a lubrication problem during the warranty, Mazda could deny your warranty claim.

I've also heard of problems with the oil foaming (IIRC) when using 5W30 in place of 5W20. May have been a specific case or cases with a certain car, but I am not willing to take a chance.
 
Ummm. I'll insert my opinion here, too. I would use the 5W20. Reason being is if there is ever a failure due to a lubrication problem during the warranty, Mazda could deny your warranty claim.

I've also heard of problems with the oil foaming (IIRC) when using 5W30 in place of 5W20. May have been a specific case or cases with a certain car, but I am not willing to take a chance.


Nonsense. 1st, your not going to have a lubrication related failure. 2nd, if you did, Mazda would have to prove it was due to the 5W-30 oil. 3rd, provide some proof that 5W-30 oil has a 'foaming' problem.
 
Even if, in my turbo engine I'll take 5W-30 thx.
BUT you should still use what 5W-30, its what's best for the Engines longevity.

I use 0W40 synthetic in my turbo Audi! (I worry about those cold starts in the winter, so the thinner 0W gives me peace of mind).

Audi/VW has had to release numerous bulletins concerning oil quality due to some engine oil sludge issues they have had. So in that case, if Mazda only lists 5W-20 as the recommended oil, I wonder if this could come to bite you if anything happens.
 
I use 0W40 synthetic in my turbo Audi! (I worry about those cold starts in the winter, so the thinner 0W gives me peace of mind).

Audi/VW has had to release numerous bulletins concerning oil quality due to some engine oil sludge issues they have had. So in that case, if Mazda only lists 5W-20 as the recommended oil, I wonder if this could come to bite you if anything happens.
5W-30 Is like the one of the best for turbocharged engines, per the Mobil1 site, and my mechanic.
 
You aren't a Lubrication Engineer and it's just your opinion.

Everyone has an opinion.

It takes a little education and work to have an informed opinion.................
NO, YOU still have not PROVEN what I said to be incorrect, what YOU'RE saying is an OPINION.
EXPLAIN......................
 
NO, YOU still have not PROVEN what I said to be incorrect, what YOU'RE saying is an OPINION.
EXPLAIN......................
What you said was your opinion...Why must he prove to you that you stated your opinion?
How about you prove that your statement was a fact?
 
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