Ok I don't endorse this product but I got curious. I use AMSoil's PI additive in my Audi so I wanted to see what the actual costs were for this stuff.

Generally with these additives you don't add the entire bottle to the tank. You add 1 oz or so per 10 gallons of gas. You may put half a bottle at the first fill up but never an entire bottle. It's not like the Techron fuel injector system cleaner bottles at Bumper to Bumper. That's the first mistake that you are all considering.

Here's my math:

1 oz additive = 10 gallons gas

1 case = 8 bottles x 16 oz = 128 oz = 1280 gallons of gas

$134.95 for 8 bottles = $16.86/bottle at the 1 case rate

$16.86 treats 160 gallons so $0.105/gallon for the treatment

Prius... use 45mpg

45 mpg at 15,000 miles per year = 333.3 gallons of gas

assume a 10% increase in economy to 50mpg

50 mpg at 15,000 miles per year = 300 gallons

Difference of 33.3 gallons.

Assume gas at $2.50/gallonx 33.3 gallons = $83.25 in gas savings

You would need to treat the 300 gallons so 300 gallons x $0.105 = $31.50

So you could save about $51.75 per year assuming a 10% MPG increase from 45 MPG to 50, you drive 15,000 miles, and gas is at $2.50/gallon. Don't forget to add in cost of shipping, etc...

Worth it? Maybe, maybe not. you have to add it at each fillup, you have to store it. I use a similar additive (AMSoil) on my Audi and do I notice an increase? Not sure, definately not 20-35% as some of these guys advertise. Power increase? Possibly. It's basically a fuel injector cleaner that I put in at every fill-up. Since I don't know how well they do gas here and I don't have the bigger brands that do good detergents, I guess it can't hurt. At 147k miles, I only had one injector fail and that was when I bought the car.

YMMV. I'll keep using my AMSoil stuff since I have a couple of gallons and use it on 4 cars

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