Boy do I wish I could find a definitive answer to this question. I am pretty sure the answer as to why the auto manufacturers went to the requirement is because of CAFE. They get better mileage with the thinner oil and the only way they can get credit for the CAFE mileage is to only recommend the oil they get the best mileage with.
It is kinda funny (to me) when you see statements like "you must use the recommended oil and viscosity or your warranty will be void". I'm pretty sure that "recommended" does not mean "required". So, I see no reason to use 0W-20 which only comes in synthetic where I live. I am using 5W-30 Dino oil. I am not worried about voiding the warranty on my 2012 Honda. I do wish that there were some examples of voided warranties to go with the statements. But, I am pretty sure there aren't any. Please provide feedback to the contrary, if anyone has some proof of a voided warranty, or a statement in the manual somewhere that I cannot find that says you MUST follow the recommended stuff or your warranty is voided.
What's everyone think?
Dan
It is kinda funny (to me) when you see statements like "you must use the recommended oil and viscosity or your warranty will be void". I'm pretty sure that "recommended" does not mean "required". So, I see no reason to use 0W-20 which only comes in synthetic where I live. I am using 5W-30 Dino oil. I am not worried about voiding the warranty on my 2012 Honda. I do wish that there were some examples of voided warranties to go with the statements. But, I am pretty sure there aren't any. Please provide feedback to the contrary, if anyone has some proof of a voided warranty, or a statement in the manual somewhere that I cannot find that says you MUST follow the recommended stuff or your warranty is voided.
What's everyone think?
Dan