on the topic of oil ??
 

does anyone know when or why all manufacturer's went to 5w30 oil.
i grew up on 10w30 here in Texas.does it really make that much of a difference

I grew up with 10W40 in PR back in the 70 & 80s. :dunno:

However that will depend on the new technology and design of that particular engine.

5W30 is typically recommended for drivers who live in colder climates. I believe the magic number is 20 degrees F. So, living in climates that drop below 20 degrees F 5W30 is recommended, in most cases.

Aside from climate, todays engines were built with tighter bearing clearances for better fuel economy, thus using a 5 weight (5W30) is recommended.

Older engines engineered with larger bearing clearances, or vehicles with high miles more than likely will achieve ideal oil pressures running with a 10 weight oil (10W30).

Hope this helps...

That clears it up thanks.

both 5w30 oil and 10w30 oil will be a 30 weight viscosity when at high operating temperature. the first number in the designation is the cold temperature viscosity rating...

therefore a 5w30 oil is better for colder climates because it has less viscosity (flows easier) at cold temperatures.

You are correct! The 5 represents viscosity properties of the oil :-). Forgive me, I have been in the hospital for two days, without sleep, with my newborn.

Thanks for the correction!