A friend of mine just made a long trip from Oregon to New Mexico and back, after he started using MPG-Caps. Before using it he says he got 18 mpg hwy. On the trip he got 25 mpg hwy. I bought a blister pack from him but as I just filled my tank I guess I have to wait until I fill it again to start using the pills. Since then my wife and I have checked a lot of sites on-line. Some sites/people say it's the best stuff in the world. Others say it's a big scam and not to waste your money. What can you tell me about it? Really Curious?? I hope this is the right forum to ask the question.

Total scam! Texas' Attorney General proved this.

As you say, there seems to be some conflicting opinions on this. But I wouldn't trust your friends findings. Taking a long drive like that means a lot of steady highway driving. I took a long trip and my mileage increased during the trip with no additives.

Snake oil!! Take the money and run! Words of thought.
Maybe your friend recently had the vehicle serviced/new tires, something to bring that milage back up to snuff. Also, summer driving is when the engine is running the hottest of all the year, and most efficient, esp on trips.