Shell V-Power and BP Ultimate

Actually, the Prius was designed to run on Octane Rating 87 (See page 318 of your owner's manual for details). Generally speaking, higher-octane fuel will contain less energy than lower-octane fuel.

From the manual:

Toyota says the common additives like 15% MTBE or 10% ethanol work fine in a Prius, but don't use leaded fuel (obviously), don't use anything with an octane lower than 87, and don't use methanol additives.

 

What's the incentive to enhance only the premium fuel? Vehicles requiring premium need the extra help?

At least Chevron/Texaco puts Techron into all their fuels now...

 

Well, could you describe these "fancy additives?" Do any of them contain methanol or other things the Toyota engineers frown upon? That was the purpose of the post; it wasn't intended to tell you what you already know, because that wouldn't be very productive, now would it?

My inclination is that additives, used in conventional street vehicles, do very little to measurably improve fuel efficiency. Just because it may burn cleaner doesn't necessarily mean it is more efficient.

 

This is the reason for the Top Tier Gasoline program.

For years gasoline companies have been selling premium gas as 'better' for your engine because of additive packages.

With tighter tolerances on modern engines and emissions systems, detergents are indeed an important part of gasoline these days.

The Auto Manufacturers know this, and they also know that their engines and emissions components degrade if the fuel doesn't have good detergent properties.

They tried to get the EPA or DOT to mandate minimum fuel additive packages for all grades, but got no response, so they started their own program.

To be in the Top Tier program, the gasoline vendor must certify that every grade of gasoline they sell has Auto Manufacturer approved additive packages with minimums for detergency and other specs.

TOP TIER Detergent Gasoline is a recently established new standard for gasoline performance. Four of the world's top automakers, BMW, General Motors, Honda, and Toyota recognize that the current EPA minimum detergent requirements do not go far enough to ensure optimal engine performance.

Since the minimum additive performance standards were first established by EPA in 1995, most gasoline marketers have actually reduced the concentration level of detergent additive in their gasoline by up to 50%. As a result, the ability of a vehicle to maintain stringent Tier 2 emission standards have been hampered, leading to engine deposits which can have a big impact on in-use emissions and driver satisfaction.

These automakers have raised the bar. TOP TIER Detergent Gasoline help drivers avoid lower quality gasoline which can leave deposits on critical engine parts, which reduces engine performance. That’s something both drivers and automakers want to avoid.

The gasoline companies who have certified their fuels (every grade in every station) are:

QuikTrip
Chevron
Conoco
Phillips
76
Shell
Entec Stations
MFA Oil Company
Kwik Trip/Kwik Star
The Somerset Refinery, Inc.
Chevron-Canada
Aloha Petroleum
Tri-Par Oil Company
Shell-Canada

Shell is a member, so you can be sure any grade you buy there is good.

Chevron is also, but note that they haven't gotten all the Texaco stations set up yet, so Texaco is not certified. They have announced that they are going to be soon.

BP apparently hasn't decided yet.

There was another thread on here about buying the most expensive gas you can find.

I think everyone would be better served if instead, people used the power of the purse to support gasoline that is the appropriate grade for the vehicle, but still keeps your emissions down.

 

Wow i didn't know that, thought it was some marketing strategy to make you put up with the more expensive gas prices. Chevron's my fav.. and Shell