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5-20 oil

My 2007 Dodge Dakota’s manual says to “Use SAE 5W-20, API Certified, meeting material standard MS-6395.”

I’m concerned that 5-20 might not be enough protection for blistering Southern California summer days especially pulling a trailer and I’m considering 5-30 instead.

Comments please.

We don’t really know. (Ok. If somebody really knows, speak up!). Why don’t you call Chrysler Field Services and ask. If they say to ask the dealer, ask them to not brush you off so readily.

You can get a lot of conflicting information with the way you posted the question. You also need to do some of your own research. First, run a Google search on the excat spec number for the oil from Dodge. When I did that for my Ford Explorer, I found that most major oil brands fit the spec if they are rated ‘SM’ from API (American Petroleum Institute). Look for the API badge on the bottle of oil, and the rating is in the middle.

As far as grades, this is a subjective thing. My Ford oil spec did not specify oil grades at all. Most car manufacturers are recommending lower weight oils as a fuel saving issue. But, my research from various oil studies show a higher weight oil significantly improves wear protection. On another note, owner’s manuals used to include an oil chart to show a range of oil weights VS ambient temperatures that are OK the the engine. My 2000 Explorer did not have a chart. Just a single recommendation for the use of 5W-30. I live here in GA, and the summers are hot and humid. In the Spring to Fall months, I use Castrol Syntec 5W-50 to help combat the heat. Underhood temps seem unbearable when stuck in Atlanta traffic. It the winter months, I use 5W-40. I stick with the low-temp weight of 5W because of the quicker protection on start-up, where the majority of engine wear occurs. This is very important in the winter months, as the cold makes the oil thicker and more viscous (resistant to flow). So far, I have 177,000 miles with NO oil related problems.

I like hellokit’s suggestion.

My personal unsupported by the thought process opinion is that it is not really important.

In you case I would use 5w30. It will likely result in slightly less mileage and slightly more life and I believe it would be a wash. If you take the trailer out of the picture I would stick with the recommended 5w20.

Does your manual suggest other options for hot climates? Most do.

Hot California temperatures and towing a trailer? This is an application where a synthetic oil should be used. A synthetic oil will be more stable against thermal break-down under these conditions than a regular oil.


Use what the manufacturer recommends. First of all they do hundreds of thousands of miles of testing to verify what is best. Second of all they have a vested interest in making that engine last longer (better reliability = more sales). Third of all if the oil they recommended was not appropriate they would be making MANY warranty engine replacements.

Ironically, using a thicker oil for “more protection” may void your warranty.

Good luck.

remember that the greater the viscosity range on the oil, the more catalysts and other viscosity enhancers means you actually are getting less oil. The spread of 5W-50 oil is actually too great in my opinion, except in engines that are designed for this type of oil, say the M3 or equivalent in BMW high performance engine. And BMW is VERY specific about the Castrol Sythetic Oil as well, recommending only the one manufactured in Europe, not USA

People who have lived in tropical countries will testifiy that there is a habit of putting 20W50 in alll vehicles, regardless of what the book says. Those countries do not have CAFE standards, and the manufacturer does not have to specify thin oil to get the mileage up at the expense of engine life. In Malaysia the daytime temperature is about 95F all year, and at night it drops to about 75-78F. Service stations carried 10W30 as their thinnest oil. The best sellers are 20W50 in both regular and synthetic. The local oil company is also the majority shareholder in the national car company, Proton!

As mentioned in previous posts, the manufacturer has 2 objectives:

  1. Get the AVERAGE car engine to last past the warrasty period; some failures due to lubrication are acceptable.

  2. Meet the CAFE mileage standards without penalties.

You, the owner, have as objectives:

  1. Oil has to be thin enough for easy starting when cold, and no oil consumption in normal use.

  2. You want to maximize engine life (250,000 miles or so), so the car will reach the end of its life without an engine overhaul. This requires oil with enough FILM STRENGTH to withstand severe conditions, should those appy.

  3. You want to meet the manufacturer’s oil spec requirements only during the warranty period

  4. you want reasonable gas mileage

My Toyota does not mention 5W20 oils anywhere, while Ford and Mazda’a do. Forget about the myth that those cars have “tighter tolerances” so that 5W20 and 0W20 are necessary.

Toyota later issued a bulletin that certain 5W20 oils would be acceptable, no doubt due to the CAFE pressure since they started selling gas guzzlers as well…

Many years ago there was an ugly lawsuit between Castrol and BMW. When BMW started selling cars in the US in quantity, the engineers in Bavaria did not change the oil spec, which was 20W50, I believe, in Germany (since BMWs are normally drive at very high speed there)and US drivers just followed the book.

Imagine a lawyer or doctor in Minnesota who follows this advice and tries to start up his car on a very cold morning. There were many engine failures, and BMW blamed them on Castrol. Needless to say, the fault lay with BMW not taking in account US drivng conditions which have low highway spoeeds, but severe starting conditions.

BMWs now need oils for their specific requirements, and the US Castrol spec is different from the European, since very long oil drain intervals are virtually legislated in Germany to reduce waste oil. This requires a lot more additives.

Smart BMW owners here ignore this long interval and change oil more in line with US practices.

What this and other posts reveal is that oil specs and drain intervals have an environmental, energy efficiency aspect that has nothing to do with engine life.

Agree; if Ford wants you to use 5W20, even when towing a trailer, you should use a full synthetic such as Mobil 1. My son has a Mazda 3 with over 60,000 miles on it. From the 3rd oil change on he used a 0W30 synthetic in the winter and a 5W30 synthetic in the summer. The engine uses no oil, runs like new and may outlast the rest of the car. Temperatures range from -10F in winter to 95F in the summer.