Don't believe the hot-weather-never W20 myth. The 0W-20 at optimally hot engine temperatures gives the same protection as the 0W-30 or 5W-30. Since 90% of engine wear happens during first starts in the morning, the lower weight 0w-20 will give BETTER protection to your engine, and that means less wear. At hot operating temperatures, both 20 & 30 are near identical in viscosity, and for practical purposes give the same protection.

I use 5W-20 during summer and 0W-20 during the other 3 seasons, and in So. Cal it can average 95F or more during the summer.

a local(orlando,FL) mechanic has a radio show in which consumer advocate issues are a large focus. anyway, he claims there are lube problems in ford cars, especially v8 motors which use 20w and the manufacturer recommends it.

having said that, not sure if there would be an issue with syn oil of this weight. also smaller engines may not have an issue. lastly, this may be only an issue in very warm climates. maybe combinations apply?

so, as always, i consider there could be different strokes for folks or cars.

It ran smoother.

While the Amsoil 0w30 is a great lube, their 0w20 is still a pretty good lube in my experience.

And remember, synthetic oils generally THICKEN (get higher weight) when they wear out, vs conventional oils that THIN (get lower weight) when they wear out. That point is significant, because it means that a good synthetic allows you to start with an oil that is just think enough to do the job, and it will continue to be thick enough for the entire life of the oil. OTOH with conventional oils you have to start with an oil that is much more thick then needed, in order to have the oil still be "thick enough" when it wears out. So it's not unreasonable to expect that a car which is designed for 10w30 (or 5w30) conventional oil (which THINS as it wears out) might be able to handle a good synthetic 0w20 (which will never be any thinner than the initial 0w20 weight, and will in fact thicken over time). Of course, if you really want to be "safe", just go with the 0w30, and then you are sure you are within engine specs.

FWIW: On my CRX, I currently put in 1 or 2 quarts of 0w30 when I first change my oil, and the rest (including any "make up oil" while driving) is the 0w20 stuff. And that approach seems to work pretty well. Again, the idea is that as the oil ages it actually thickens, so going with the 0w20 for some of the oil in the initial mix (and all of the "make up oil") still leaves me with an oil that seems "thick enough" for the job (without having an oil that gets "too think" over time).

As to oil and filter changes; unless you drive to the corner grocery and three miles to work, in otherwords very hard use, you'll do fine changing oil and filter at 25,000 miles. Get an oil analysis half-way, for the engine and transmission just to satisfy your curiosity. You'll have a baseline for later analysis anyhow.
Extended oil changes worked fine for me on my last vehicle, my Dakota. The engine and transmission managed to last 623,000 miles with Amsoil.

The picture of your engine looks like a 4-banger.
The Amsoil site has a place: AUTO AND LIGHT TRUCK LOOKUP GUIDE over to the right, and it says the 4 cylinder engine uses 30 weight oil.

If your engine is tight and in good condition, and you are a very gentle driver, you can maybe might get away with using 20 weight oil.

GM put a wad of engineering money into designing that engine and they specified 30 weight oil because of the lubrication and protection requirements. They had 20 weight then, but chose 30.
You'd feel silly, having to replace something like a camshaft because you used the wrong oil.

On the other hand, Amsoil can handle some incredible abuse.

interesting this thread got bumped...

today, my consumer advocate mechanic talked about amsoil vs mobile1 on his radio show.

besides the higher quality base, it has an ingredient that mobile1 does not have. can't remember the name, but it serves to make/keep seals soft which prevents them from leaking.

today's show if you have time to listen...

https://www.streamaudio.com/Player/Pl...3pm.wma&OptIn=

https://wdbo.com/ads/ate_themagicmechanicshow.html

ok, i relistened. the ingredient is esther(correct spelling?).

It has been about a year since you changed over to the 0-20 Amsoil, so I was wondering how you were making out since the change.