A few weeks ago, Ed Schultz interviewed a representative from CMH industries about a new product - a fuel additive called "CA-40". The tagline of the product? "Guaranteed to save 10% on fuel economy".
The website is purposefully vague on the chemistry, but basically it's supposed to both assist in the separation of fuel hydrocarbons, and utilize super-solubilized calcium to generate a "secondary spark" upon heating. The theory is that it provides for a cleaner, more efficient burn, which results in more power during the power stroke of the pistons.
I bought some of the additive, and tested it out in a tank. So, did it work?
Short answer: no, with reservations.
Minutiae and caveats below the fold.
The biggest most glaring caveat to my limited analysis is that I am driving a non-standard vehicle which is already optimized for fuel efficiency. Other caveats include limited testing, and statistical variance in my "normal" fuel economy. I admit up front that I don't have a full set of data here, so if you want to try this additive for yourself, by all means try it. I'd love to hear your results. Also, in the interest of full disclosure, I am in no way affiliated with CMH industries and have no financial interests in either them or any of their competitors, to my knowledge (what my IRA does is its own business, but I don't believe my portfolio includes fuel additive). I am only a consumer.
I am now driving a 2007 Honda Civic Hybrid. I've only owned this vehicle for a little over a month. My daily commute to work is around 75 miles, plus whatever I happen to drive on weekends. I drive using highly fuel-efficient methods, including
- Keeping the speedometer at or below 65 unless I'm passing
- Using Cruise control whenever possible
- Neutral coasting
- Avoiding red light creep (creeping disengages the hybrid's "auto-stop" feature)
- Never using the air conditioning
I have filled the tank on this car a total of 4 times so far. While it has a "miles per gallon" readout feature, that tends to be inaccurate, so I measure total gas input at a fillup and then use that to divide by the trip readout on the odometer. The first trip, when I took posession of the car, I got 46 mpg. This was while I was still in poor efficiency driving mode, going over 75 and blasting the air (plus I have no idea how many people test drove it before I did and whether or not they reset the odometer). Second trip: 52 mpg. 3rd, 49.5 mpg. There's natural variance based on how many city miles I drive, and whether my wife is in the car (she likes a little air, and I can't argue being that she is uncomfortable enough carrying my child inside her at the moment).
The manufacturer mileage is stated at 49 city/51 highway. So I'm more or less within the manufacturer's fuel efficiency range, probably a bit above, all things considered.
Last week I added 15 ml (~ 1/2 fluid ounce) of the CA-40 additive to a tank that holds a little over 11 gallons. The recommended mix ratio from CMH is 1 oz per 15-20 gallons of fuel, so I may have been a squinch on the dilute side for the additive. Still, it promises 10% increase in fuel economy, which based on what I'm getting ought to be in the neighborhood of 5 mpg better.
I drove on this tank all week, just about finishing it out last night. Odometer read was 519.9, and I added 11.06 gallons of regular unleaded. In case you don't have handy access to a calculator feature, that's 47 mpg. Ouch!
Now, even with the caveats in mind, this product is not even performing close to its promise. It is supposed to increase mileage by 10%. It actually seems to have decreased my mileage by 5-10% instead. I wasn't driving significantly differently. I did get stuck in a couple traffic jams, but never for more than 10 minutes at a time, and the hybrid usually takes care of such things with the electric assist and auto stop features. Anyhow it's not like I never got stuck in traffic when I was getting 52 mpg.
This morning on my way into work, with a fresh tank and no additive, my mpg feature is reading 55 mpg. The same time last week with an additive-spiked tank, it never got above 51. I have to conclude that this additive simply does not work with my car.
Extended analysis - I can't say for certain that it doesn't work. I can't address the "decreased emissions", as I'm not equipped to measure such things. And my vehicle is already optimized for fuel efficiency. It is possible that fuel burn is more tightly controlled in the hybrid so that a more powerful stroke just won't matter. It's also slightly unfair to expect 5 mpg difference in the hybrid, because part of the regularly great mileage is from an electric engine that has nothing to do with fuel combustion. Still, the same engine in the non-hybrid civic gets 35/40, so I'd still expect a 3-4 mpg increase. Definitely not a 2-4 mpg decrease.
For all the naysayers out there - too good to be true? Yup. At least for 2007 Civic Hybrids. I'm going to try to convince my wife to use an aliquot of the additive in her 2002 Ford Focus and see if there's a positive impact there. I'd also love to hear from you if you've had any experience with this product.