Premium vs Super Unleaded (10% Ethanol)
 

Hi! I have a 99 Deville, Northstar. I thought I had read somewhere that using anything other than premium fuel would damage the fuel injectors (and other things - I'm rather mechanically disinclined). The display clearly says "premium fuel only." However, I have people telling me differently.

I've ALWAYS used Premium, but, today, Premium(no ethanol, 91 octane) was 3.72 - SIXTY CENTS a gallon more than the Super Unleaded (10% ethanol, 89 octane). So, about $10 more each time I fill. I was stunned, it used to be 10 cents more or so.

I LOVE my car and don't want to hurt it. I've looked around and couldn't really tell if it made a difference or not - too many conflicting opinions.

I don't know if this matters, but, I've had the car for 8 years now,and it has right at 101,000(give or take 100) miles on it.

I work from home, so I don't drive every single day, and it's horridly cold here in Iowa (as the rest of the country, I know), and I have no garage. I don't want to change fuel grades if it will cause harm to the engine. Then again, I don't want to give those jerks any more money than I need, either.

I thank you, in advance, for any answers.