I drive a 2005 CR-V EX AWD, original owner, 102k miles and have performed regularly scheduled maintenance. My question is about using a different oil viscosity than recommended in the Honda owner's manual. My CR-V owner's lists 5W-20 as the only acceptable weight to use. I bought a stock of about 30 quarts of oil recently on a closeoout and got a great deal. Most of the oil is Sunoco 5W-30 dino, and there's some Castrol GTX, Pennzoil, and Valvoline in the mix also, either 5W-30, 10W-40 or 10W-30.

I haven't been able to determine yet if these oils are safe to use in my CR-V, and I haven't found much on-line. I know that some of the push to lower weight oils is part of the push from CAFE standards to improve fuel mileage. But I also heard on a "car-talk" radio show a while back that because modern engines are manufactured to much higher tolerances than in the past, that higher viscosity oils may too thick to get into tighter clearances between components-bearings, etc.

Does anyone really have a definitive answer on this? Would it be safe to use the 10W-30 in summer, and stick to the recommended 5W-20 in the fall and winter?

 

"bob is the oil guy". this is where you'll get the best info on this subject.

personally i'm more concerned/focused on how clean (light) and fresh the oil is and less on the grade/weight.

for your CR-V a 5W-30 won't likely do any harm. this was spec'ed in the older hondas and the clearances are not too different. you may see a slight drop in mileage, nothing dramatic and possibly more valve train noise when it's cold.

the thought of using 10W's makes me cringe... but i don't have any empirical data to offer. check the forums and Bobistheoilguy. they'll be able to give you a straight answer.

 

Ah "Car Talk", the laughing stock of the automotive industry.


Of course even a broken clock is right twice a day and in this case Cartalk is correct. The biggest harm will come during cold starts. While the damage will not be immediately appearant, it IS occurring with the incorrect oil viscosity. Additionally you will in all likely hood set a variable valve timing code because the proper weight is required for the actuation of the solenoids and variable gears(if applicable)......




(BTW Bob is The Oil Guy used to have actual engineers and chemists from the various oil companies on the site. Now its mostly just a bunch of internet know -it- alls. Id take the current info with a grain of salt. But the info found in the archives is gold and mostly still holds true.)

 

This link will take you to the most informative cache of oil knowledge on the internet: https://540ratblog.wordpress.com

I run Rotella T6 5w40 in every internal combustion engine I own.

 

Riiiight because it is written by an "engineer" who designed his own test sequences, but provided no EOT data. Who dismisses millions of dollars in R and D because he simply has all the right answers.......LoL gotta love the internet.



Many people run straight water in their cooling systems for years with no problems.



Its all good until its not......

 

​The guy is a consultant for several leading NASCAR teams.

 

 

Dcceiver: After reading bobistheoilguy I get what you're saying about the start-up lubrication. That said, shouldn't the start-up lubrication/viscosity be the same with a 5W-30 as with the Honda recommended 5W-20, as they both have the same flow characteristics at startup-the 5W in the grading?

 

Means nothing. He provided no empirical data or End Of Test results to supports his claims. He changed the testing sequence to meet his criteria and did not even TOUCH the subject of manufactures testing.


API certification considered the minimum standard. Every vehicle manufacture has test sequences and oil specifications for every engine they build, and their sequences far exceed traditional ASTM testing.




The guys blog is grandiose and self serving.....

 

The wieght of the oil is only part of the story, the additive packages are completely different.

 

Cliffs:

• It depends on your climate: cold vs hot
• It depends on how you are going to drive your car: racing vs daily driving
• It depends on the oil
• You need to have your oil analyzed by a lab

In general you can't go wrong with the manufacturer's recommendations. If you do decide to go rogue and use something not recommended by the manufacturer then you need to do your due diligence and get your oil tested by a lab as well as monitor your oil pressure and temperature. Most people are not willing to risk their engine by using oil that is not recommended by the manufacturer. This is why you haven't been able to find what you are looking for. Those that do have either modified their engines heavily or have found that the OEM recommended oil is not up to the task for the owner's intended use. IMO, it no longer makes sense to buy conventional motor oil anymore. Quality synthetic oils are so good at what they do that you could really go for a year or 20k+ miles without an oil change. It may seem like you are paying more up front but in the end the time spent not under a car changing oil is well worth the extra cost.