Dear Tom and Ray:
I'm not a rocket scientist, just a veterinarian, but I can't figure this one out. I have a 2000 Subaru Outback. The owner's manual tells me that I should only use ethylene-glycol-based antifreeze. But I know that stuff kills so many animals, and I want to use the animal-friendlier propylene glycol. In fact, I can't for the life of me figure out why anyone would still use ethylene glycol when this safer alternative exists. Is there any reason I shouldn't use the safer antifreeze in my car? So many innocent lives would be saved. -- Janice
RAY: The country needs to get embittered about this, Janice.
TOM: Sadly, most new cars now come with long-life, organic coolants. These are all ethylene-glycol-based, and they're all poisonous to neighborhood dogs and cats. And worse, they smell and taste sweet, so when this stuff leaks out of somebody's engine, animals lap it right up. It takes only a few tablespoons of ethylene-glycol-based coolant to cause kidney failure and death in an average dog.
RAY: So, several companies (Peak's Sierra, most notably) came out with a safer coolant based on the chemically similar propylene glycol, which is much less toxic. Not everybody switched to it, because it's more expensive. But it's a perfectly adequate substitute for any car that uses regular old (non-long-life) coolant. In fact, it's probably fine for your Subaru. But some manufacturers will void warranties if you don't use the coolant they specify, so you shouldn't take that risk.
TOM: As far as we know, there are no long-life coolants -- which is what Subaru and others now require -- based on the safer propylene glycol.
RAY: But here's why we all need to get embittered. California and Oregon now require that any coolant sold in those states be "embittered," so that it tastes awful to dogs, cats or little kids. The manufacturers do that by simply adding a chemical "stink agent" that costs about 2 or 3 cents a gallon.
TOM: It's the same stink agent that was originally identified by Lawrence Livermore Laboratories in my brother's gym bag.
RAY: It's an idea that's overdue. So, if you don't live in one of those states, you need to start demanding "embittered" coolant at your local auto-parts store. And Janice, you can help educate your clients and encourage them to do it, too.
TOM: The good news is that in our experience, trends that start in California eventually spread to the rest of the country. So I think it's only a matter of time before every state is embittered.
RAY: I'm feeling embittered already!