do I have to run 100% gas 2012 prius c?

welcome! nope. are you considering diesel or kerosine?

 

Your car is designed to run on E10 gas. That is 10% ethanol. We don't like it, but it works fine.
X

 

E10 gas is fine. More than 10% ethanol is discouraged by Toyota.

(it will get about 4% less fuel economy than pure gas but usually cheaper per mile)

 

and you will get 10% less mpg's. what the price diff?

 

not successfully, without some changes.

 

Diesel is always a bad choice.

Toyota does not think you can run E85. If your warranty is up, (60,000 miles) then their opinion does not matter as much. Best of luck. (if you find a E85 conversion for a Prius, expect 30% lower MPGs)

 

how much diesel would you mix in?

 

First of all.....diesel is more expensive than gas, so I'm not sure what you'd accomplish by trying to use it as fuel in a "C-Type" other than a good way to see if the "check engine light" or CEL is working.

As far as E85?
Bob Wilson did some tinkering with this a while back, and I'm thinking that he's not using E85 now.
Read up on it yourself and TIFWIW.

Me?
I like posts like this because all of the financial experts out there say that it's moronic to buy new cars instead of used ones----and they're right.
However (comma!!!) there are enough people out there who engage in physics and chemical experimentation with their cars that I can use as an example to my CFO when it comes time for me to retire one of my vehicles, that I'll be able to get a nice new one instead of a "gently" used one.


Your car.
Your call.

I don't.
I won't.

Good Luck!

 

is this something you've tried with other vehicles?

 

81k is a little short to need a 'major tuneup'

http://www.toyota.com/t3Portal/document/omms/T-MMS-12PriusC/pdf/2012_Toyota_Prius_C_WMG.pdf

at 90,000 miles it needs a new air filter (page 49)
at 100,000 miles you should replace both coolants, engine and inverter (page 50)
at 120,000 miles it needs new spark plugs and another air filter (page 53)

You might consider doing the plugs and filter early to improve MPG

but I suspect you are just driving it short distances.

 

I'd say it's designed to tolerate gas with up to 10% ethanol. It'll do better with 100% gas, and I believe that's what's used in the mpg tests. All moot, since 100% gas is rare, and expensive if you can find it.

 

i suppose you'd have to run some mpg trials to see which is more economical. unfortunately, you're driving the most economical car on the road. gonna be tough to improve on it. pump up your tyres and through all the excess weight overboard.