Oil Spec 5W20



Our 10-month-old Honda has one of their new “Maintenance Minder” to tell you when to change the oil (Click & Clack say to believe it rather than a general guideline). Honda specifies 5W20 oil. In hot weather, would 5W30 be ok as long as it carries the SAE seal? Is there some intrinsic difference between 5W20 and 5W30 other than the obvious high-temp weight?


one is thicker, any kind of oil will be “ok” (except penzoil) (it sucks) but the recommended oil will be better.


One difference is a possible drop in gas mileage with the higher-viscosity oil. That is the primary reason why car makers have gone over to the “lighter” stuff.

Also, the very tight clearances in the newer engines make the “lighter” oil more effective at lubricating. I would recommend that you stay with Honda’s recommendations. In fact, using the wrong viscosity could possibly void the warranty if it was discovered. (How they would discover it is unclear to me, but…)


And why does Pennzoil suck? Is it the wax again?



The 5w30 has more VI’s (viscosity improvers) which do not provide lubrication


penzoil is very bad for your motor, local mechanics always say “i wouldnt use penzil to start a fire” overhaul a motor and you can always tell if it has used penzoil


Other than anecdotal evidence, is there any actual proof that pennzoil is bad? I can get mechanics to tell you all sorts of things, doesn’t make them true. Oil questions are best answered by a tribologist anyway. I am willing to hear any actual proof though.

PS- I don’t use pennzoil, nor own stock, nor work for the company, but continuing urban legends rubs me the wrong way.


my lawnmower ran off penzoil, went to overhaul, bam! nastiest mess of sludge and crap i ever saw, never happened again after i stopped using it.


I’m tired of mowing my yard. I think I’ll fill the lawnmower crankcase with Pennzoil and put an end to this hard work.


thats the spirit!


We had a terribly dry summer in my area. Even though I heavily watered my garden, the corn was so stressed that it tassled too early and didn’t produce. I only got 3 meals from all the beans that I planted, and of all the squash that I set out, only 2 were produced. However, I didn’t put a drop of water on my lawn. It turned brown and I didn’t have to mow for about 2 months. After a couple of heavy rains the past 2 weeks, it pulled out of it and I had to mow it twice in a week. I think I’ll learn to graze–I can have something to eat and I can forget the lawnmower.


My Honda CRV’s transmission had a bearing go bad at 35,996 miles. Clearly all Honda transmissions have bad bearings. Or perhaps this was an isolated case?



Both are 5W oil base, so the viscocity extenders are the main difference. Generally speaking, the less difference between base weight and hot (working) weight, the less viscocity extenders there are in proportion to base weight oil. Viscosity extenders are not bad, in fact they can in effect automatically adjust the lubricating properties of the oil with temperature cycling. Where you get into trouble is that a large range requires more extender and/or larger molecules, which in turn break down more readily over time.

The best advice is to use the oil the mfr specifies and forget trying to re-engineer your engine by varying from what professional designers built the engine around. An oil that works perfectly in one engine may kill another engine.

Multi-weight oils are another prime example of why you should shorten change intervals to lessen the effect of these breakdowns.


Not if you want to keep your warranty intact.


Just another “old mechanic’s tale” as far as I’m concerned. Where I grew up it was always Quaker State that the local mechanics said would gunk up an engine.

I didn’t believe them either.