So, I've only had my Prius for under two weeks, and I've been putting Premium gas (91)in it, but was wondering what other Prius drivers were using? I've been trying to be good to my car since it's brand new, but was wondering if anyone has noticed any drop off in any of the lower quality gases? Premium is getting a little expensive in Cali, it'll hit $3 in the next few days and I can't afford it with my 200 mile commute round trip.

Toyota does not recommend using Premium or high octane. It was designed to run on 87, so I'd do that. I would even suspect that you might have taken an MPG hit by using 91 (92 where I'm at) instead of 87.

As for that stuff about additives and detergents in the premium gas grades, it is bunk. 87 has all the additives and detergents you will even need.

So, save some money and buy the least expensive fuel you can find and enjoy the ride.

It has been said:
Hybrid drivers come in 3 flavors, greenie, techie and cheapie. Pick any 2.
2005 Prius, Melinium Silver over gray, package 5 (AI)

Hot ****! If that's true I can really start saving money, I haven't seen any sort of hit on my MPG, but if it goes up I'll know. Today I drove 100 miles plus, at the speed limit up a big hill (or mountain, it's a steady 2 or 3 mile climb, whatever) anyway, I ended up at about 51 MPG, so I won't complain, but if I can squeeze another couple miles out of lesser quality gas, I'll be happier. Plus, I can spend that extra money on a new set of speakers for my ride!

It's true. 87 octane only :-)

91 octane is for high compression engines. It actually burns slower than 87 so if you put it in a low compression engine it doesn't all burn meaning less power from the same amount of gas as if you had used 87 octane. Kevin

2004 silverblue 5 sp.

i dont think using a higher octane fuel than recommended is actually good for your engine. stick to the 87 prescribed by your car manual, and try to go to the same company gas station to fill up for consistency in gas content. i always use arco, which is the cheapest around here, and 76 if i have to.

chevron has the best gas, but is also among the most expensive. if you really love your car, put in 87 octane from chevron

Thanks guys, I was wondering if it was a waste of my money. I figured if this was a car that is intended to save you money on gas that it would work fine with 87, but at the same time, I was worried since it is a new car, and it's my first that I'd start to wear it down before its time. I usually gas at Costco since it's on my way to work and it's much cheaper than any other gas station, plus there's almost never a line.

I try and get my gasoline at Sam's Wholesale when it's conveinient (Same as Costco) but several QuickTrip's (Among the lowest gas $ chain) are right on my route.
Quicktrip is usually a couple of pennies/Gallon above Sam's.

Personally I've seen zero decisive performance differences between the least and the most expensive brands. Operational cost was one of the reasons I bought a hybrid so cheaper is my choice.

Efficient drivers do it better.
1003 miles a tank personal record. 74MPG calculated. HCH1 CVT

I used to have some contact with a guy who hauled fuel from the tank farm or refinery to gas stations. He hauled to a number of different brands of station, however usually started out at the same place to fill his truck. Well, turns out that gas is mixed with additives at the point of tank truck filling. So, if he was hauling for Chevron one day he would have a formula code on his documents which he would punch in to the filling pump which would put their additives in as the truck filled. Another day he would be hauling fuel to a Costco and a slightly different code. The moral of the story is that gas comes from the same place, but gets different additives based on the retailer, however the actual amount of gasoline in a gallon of gas is basically the same from brand to brand. Therefore, buy the cheapest gas you can find and enjoy your new found savings.

It has been said:
Hybrid drivers come in 3 flavors, greenie, techie and cheapie. Pick any 2.
2005 Prius, Melinium Silver over gray, package 5 (AI)

Honda, GM, Toyota and BMW developed a gas standard called Top Tier to address the declining level of detergents in gas. Currently certified are Shell, ConocoPhillips, ChevronTexaco, QuikTrip, and a few small ones. go to www.toptiergas.com.

To be certified all grades (regular included) at all stations must meet the standard. The certification simply means the gas from those certified meets whatever standard the 4 car companies developed. Other brands are probably fine, but haven't been checked and aren't certified.

Since it's the same price as far as I'm concerned, I always fill up with one of these brands, only Shell or Phillips in my area. I never use the "super cheapie" that are much cheaper than everyone else, I've been told they purchase "out of code" gas that major manufacturers won't use anymore, and that's how they get their gas cheaper than say Speedway, Thortons, and the other "discount" brands.