Which oil to use

I have an 06 honda CRV I know it calls for 5/20 motor oil but sometimes if 5/20 is not on sale & 5/30 is I use the 5/30 Do you think that could cause any engine problems later on. Some people tell me I should only use the 5/20. I only have 40,000 miles on it ,so far it runs smooth & quiet .

I would stick with the 5w20. Its probably mostly for fuel economy, however that’s what its designed for so use it. Stock up on 5w20 when its on sale.

Take a close look at the owner’s manual. For example my truck calls for 5w20 in the US, but if I lived in Canada apparently 5w30 is ok. Keep in mind that if you have variable valve timing the motor oil may also acts as a hydraulic fluid, so the different viscosity may affect performance.

Also seems strange to me that a retailer would differentiate between oil weights on a sale. I just picked up five quarts each of Castrol Synblend and High Mileage and two filters on sale. The price was the same.

A lot of newer engines use oil-operated apparatuses to enable variable valve timing and cylinder deactivation, which may not function right with the wrong weight of oil, plus the tolerances are so tight that you might not get proper lubrication with too thick of an oil. The difference between 5W-20 and 5W-30 isn’t drastic, but over the long term, who knows? I would stick with what the manual recommends.

Regarding the possibility of 5W-30 adversely effecting a variable valve timing and other mechanism, speculation on that has appeared more than once on this site. At this time, nobody knows for sure; I have not seen an engine designer on this site. The same speculation could apply to hydraulic valve lifters but that has not been mentioned. Our GM car’s owner’s manual specifies 5W-20 but does not forbid 5W-30. There are other oil weights such as 10W-30 that it does specifically forbid.

Carefully read your owner’s manual for direct instructions and also for what it does not specifically mention.


Are you a Costco member?

Costco carries 5w20 and they have it on sale every few months.

Isn’t motor oil generally put on sale by brand and not weight? And isn’t one brand of oil on sale any given time? I’ve never seen an occasion were Pennzoil 5W-30 was on sale and 5W-20 wasn’t.

“Costco carries 5w20 and they have it on sale every few months.”

Unfortunately, the Costco stores in my neck of the woods sell only Mobil-1 in the 5w-20 viscosity.
For those who want “conventional” 5w-20, we are left with only Wal-Mart if we want to buy motor oil at a decent price.

The weight (viscosity) is important, but it is not the whole picture. Two cars may call for 10W30 but may need different oils. Cars are more complex these days. So please check with the car’s owner’s manual for your make model and year. You also may want to consider different oils for cars used in different local weather conditions.

Don’t get your oil changed at any of the quick oil change places. Find a good local independent shop.

It’s an expensive car. Buy the recomended oil whether it’s on sale or not, when needed, as needed, whatever.

An auto engineer who designs engines made a good point recently that motors with VTEC systems (variable valve timing) rely on the proper weight oil to function properly. Your Honda has the VTEC system, therefore you should use the recommended 5W-20 Honda specs.

Oil flowing in the motor does more than just lubricate. It helps cool the motor and apparently flow characteristics are incorporated into motor design. I’m sure the 5W-20 goes on sale, but even at full price how much more does it really costs?

Quote from Uncle Turbo: “An auto engineer who designs engines made a good point recently that motors with VTEC systems (variable valve timing) rely on the proper weight oil to function properly” Unquote

I recall that the poster speculated that.

The Costco near me sells conventional 5w20, 5w30, 10w30 and 10w40. All the conventional oils go on sale every few months. They only have one brand, though.

They also have Mobil 1 synthetic oil in a few viscosities. It also goes on sale every few months.

The conventionals and synthetics are, unfortunately, never on sale at the same time.

My 2002 Sienna says 5W-30, I think, (somehow I lost the owner’s manual) though it does imply people living in extra hot places may want to move up. I have always used 10W-30, since I bought the car in McAllen. 196,000 miles and in great shape.

Interestingly, the people here in rural Mexico are convinced that cars need 20W-50 and even Autozone in Tehuacan plays that game. I tried to buy Quaker State 10W-30 and the punk in the village oil store told me it would ruin my motor. The one with 196,000 miles on it.

It is actually cooler here in the summer by far than McAllen.


Any chance that 20w50 costs more than 5w30 in your neck of the woods?

Perhaps the marketers have succeeded in convincing the population that the more expensive product is the better product . . .

20w50 hasn’t been “the norm” in a long time. Even hard working diesel engines in fleet vehicles generally don’t use 20w50 anymore. It has been “replaced” by 15w40, for the most part.

If walmart stocks cheap 5-20, than go there. U make it sound like u prefer to buy 5-30 at another store close to you, cuz it’s convenient?

Let’s see . . .

SEVERAL people mention oil on sale in Costco, Walmart, etc.

I was even nice enough to mention what viscosities they have.

I was being helpful.

Perhaps OP is a Costco member but was unaware that they stock engine oil, or that it’s on sale occasionally

But I get flagged for “off topic”


@db4690, I thought that post was on topic, and I wouldn’t worry about getting an off topic flag. I consider that sort of flag as fairly meaningless. I was with you until the last line. Maybe you should take a few deep breaths, too.

Huff and puff . . .

good job!