Originally Posted By: jtaylor
thank you Garak, I really appreciate that, what is HDEO
No problem. Someone already answered it before I got back. Basically, diesel engine oil. They're all marked as to whether or not they meet the S spec (i.e. SJ, SL, SM) for gasoline engines. One has to choose one that meets the specifications for one's particular gasoline engine, be it SM or other proprietary specifications. Check the owners manual for any contraindications or weird specifications.
For the most part, 5w-20 wasn't created because of clearances or because engineers decided they were wrong for all these years. It's because of fuel economy.
There will be a difference in measured fuel economy between a 5w-20 and a 15w40, for instance. It won't break your wallet, but when a car manufacturer has to meet fuel economy guidelines, it can be pretty significant. Over the years, we've seen all kinds of ways cars have changed simply due to satisfy fuel economy (and emissions) regulations.
When emissions technology and fuel injection were in their infancy, we saw manufacturers switch to skinny little tires to reduce rolling resistance. We saw that swing back as engine and fuel control advanced rapidly. Oil recommendations have been going progressively thinner, in the North American market at least.
In Germany, we find cars driving faster and with longer OCIs. They use thicker oils, and German manufacturers recommend them. My Audi specifically recommends a 40 weight oil, unless the cold dictates otherwise. Yet, in North America, and even here on the forums, we have posters buying the 5w-20 argument, yet wanting extended OCIs as well.
So, find something that meets the requirements for your engine and is a viscosity with which you're comfortable. If the manual explicitly prohibits an HDEO, then you're out of luck for HDEO. Otherwise, it is an option, particularly since you have been using synthetics and appropriate viscosities are available in synthetic HDEOs. GC is also a good option.
In your climate, a 5w-40 is not going to provide any problems, at least from a viscosity perspective. If I can start my Audi in -40 weather with 5w-40 in it, it is categorically not too thick for California weather.
thank you Garak, I really appreciate that, what is HDEO
No problem. Someone already answered it before I got back. Basically, diesel engine oil. They're all marked as to whether or not they meet the S spec (i.e. SJ, SL, SM) for gasoline engines. One has to choose one that meets the specifications for one's particular gasoline engine, be it SM or other proprietary specifications. Check the owners manual for any contraindications or weird specifications.
For the most part, 5w-20 wasn't created because of clearances or because engineers decided they were wrong for all these years. It's because of fuel economy.
There will be a difference in measured fuel economy between a 5w-20 and a 15w40, for instance. It won't break your wallet, but when a car manufacturer has to meet fuel economy guidelines, it can be pretty significant. Over the years, we've seen all kinds of ways cars have changed simply due to satisfy fuel economy (and emissions) regulations.
When emissions technology and fuel injection were in their infancy, we saw manufacturers switch to skinny little tires to reduce rolling resistance. We saw that swing back as engine and fuel control advanced rapidly. Oil recommendations have been going progressively thinner, in the North American market at least.
In Germany, we find cars driving faster and with longer OCIs. They use thicker oils, and German manufacturers recommend them. My Audi specifically recommends a 40 weight oil, unless the cold dictates otherwise. Yet, in North America, and even here on the forums, we have posters buying the 5w-20 argument, yet wanting extended OCIs as well.
So, find something that meets the requirements for your engine and is a viscosity with which you're comfortable. If the manual explicitly prohibits an HDEO, then you're out of luck for HDEO. Otherwise, it is an option, particularly since you have been using synthetics and appropriate viscosities are available in synthetic HDEOs. GC is also a good option.
In your climate, a 5w-40 is not going to provide any problems, at least from a viscosity perspective. If I can start my Audi in -40 weather with 5w-40 in it, it is categorically not too thick for California weather.
