How thick am I (or how thick should my car oil be)

ok, I learned to always use 20w/50 here in Florida, and have been doing so for 20 years. Now my 1988 and 2000 Honda’s say use 5w/30 ONLY and I have compromised by using 10w/40. I just bought a 2003 Toyota Tacoma and it said use 5w/30 ONLY. Well 5w/30 is kinda like water when draining from a hot engine. Do they recommend this to help the Engines to wear out sooner? Yes, I am a conspiracy believer. Maybe they do it to get higher gas mileage??

So what should I do?? I want the max life from my engines.

Also, notice that starburst that many oil cans have in addition to the API Donut?? I have only seen this starburst on 5w/30 and 10w/30 oils. API web site just barely discusses these symbols and does not tell me exactly what they mean. They will not answer my e mails, nor will several other sites that I have asked. Does anyone know what the difference is??

This all is just to heavy for me.

You should probably use what is recommended by the manufacturer, even in FL. Oils and engine tolerances have improved greatly in the intervening years. Using something other than the manufacturer’s recommended weight could void your warrentee.

They use lighter oils because the engines of today don’t need such heavy lubricants, and the lighter weight oils increase gas milage.

Follow the recommendation of the vehicle manufacturer. Modern oils are carefully formulated to have certain characteristics. Additives used in these formulations, such as film strength enhancers and friction modifiers, do a great job. The perceived thickness of the oil is not what makes it suitable and effective for protecting your engine.

5w30 is superior to 10w30 in providing lubrication throughout the engine quickly after start-up. Some car manufacturers found this out the hard way when certain 80’s design engines had worn out camshafts after 50,000 miles. Changing the oil recommendation from 10w30 to 5w30 solved the problem. Do yourself a favor and use 5w30 if that’s what’s recommended.

The starburst I see says “For Gasoline Engines.” I interpret that as meaning “NOT for Diesel Engines.”