Well the short answer is - not by your approach! It’s not a question of whether you are paying more total interest on a longer term loan. Of course you are, because time has value. It’s a question of how much more you are paying, and whether that’s a good deal. And the APR tells you exactly that. In your example, with the longer term loan you are locking in the use of money for extra time at only 1.5% per year - a very good annual rate. Even if it turns out that you can afford to repay the loan in 3 years, you could invest the money and probably generate an annual rate of return in excess of 1.5% with little risk.
Your argument appears to be that if someone is so innumerate that they cannot grasp the correct way to look at something, you should teach them the wrong way to look at it. And I don’t agree.
They still teach Newtonian gravitation, even though it’s wrong.
Many people make terrible economic decisions and explaining the right way to understand things doesn’t help them if it’s beyond what they’re willing or able to learn.
If I want someone to understand the value of time, showing them the value of time gives them something concrete to focus on. I’ve found the approach of “trust me, I know this better than you” sometimes doesn’t work. Maybe your friends and family are smarter or more trusting than mine.
Well it’s a very strange idea to remove time from the analysis as a way to teach people about the value of time. Your approach is like teaching a novice driver about speed limits by telling them to focus only on how far they have gone, but to ignore how long it has taken them.
Pleonast, Kiss it. Keep it simple silly. $6000 at 1.5% If only one payment was made at the end of the year will cost $90 in interest plus principal payment. $6000 at 3% would be $180 in interest. That interest is not reducing the amount loaned, But in reality each payment the difference will be less, but the interest will always be twice. That is an over simplified explanation.