Dingo, My first order of a magnet worked well, the only drawback was constuction. The magnets were held in place by some adhesive back velcro which under heat became goey and the magnets would clump up and slide out of position so I would not give that site. The second Magnet was from a auto parts dealer which was excellent, but I had to buy a large quantity to get a better price. Since then I have been ordering from a magnet manufacturer so if you want to build your own you can. One note magnets are useful in many ways besides just this application. I am treating my water with the same magnets. This gives a softening effect which improves taste and gives heathful effects. The Magnets will reorient the water molecules just like they do to fuel and just about any liquid. The water molecules will be spread apart and ionized so that all molecules are similarly charged so that they will repell each other thus minerals like magnesium and calcium which normally would attract and cake up on metal surfaces are left in liquid suspension and continue on there way. I have a furnace humidifier which used to need constant cleaning and pads, since I installed the magnets I haven't had to do any maintenance. Magnets are supposed to help with agriculture also. The ionized water molecules are smaller so they more easily absorbed by plants so they get more minerals than before. This ionized water is also more easily absorbed by the human body so hydration is enhanced and it tastes better too. To treat water and protect your water heater you should install one magnet to main water inlet pipe before any split offs and put one magnet on pipe just before going into water heating and one magnet on pipe just leaving water heater. Magnetic ionization is only affected by heat so water sitting in hot water tank can lose ionization after a few days. I am also trying magnets on my natural gas furnace,gas water heater,lawn mower, propane gas grill,gas stove. Magnets can be used gas generators,weed wackers Etc.
the web site is http://www.kjmagnetics.com
there is a section products then scroll down to quick links and select other items then scroll down page in right column is fuel line magnets. Click on that and you will see prices. Should be 15 for one with a drop down menu if you want more than one.
When installing the magnet you should diconnect battery for 30 minutes to reset the computer to the new fuel treatment. Sometimes computers will need 1-5 drive sequences to learn new drive parameters. I did not have to do this on my fathers car or any other cars so far but it's good to cover that base. Also as with any powerful magnet do not expose your car computer or any senitive equipment to it.
As far as seeing results I have concluded the best way to compare milage results is to drive the same route on highway driving only. On highway you can duplicate driving easier than in town which is different all the time. If that is not possible, if you have an idea what milage you get on a full tank of gas in all around driving than you can take an average milage over 2-4 tanks of gas and tell from that. When using magnets they will initially start to clean out your injectors or carb. The fuel will burn hotter ,cleaner and after about 1000 miles or so check oil and problably change it. The oil will be black with burnt carbon and problably have chunks of carbon deposits from valves and injectors will be cleaned out so your car will run like new (unless there is mechanical problems) . When i tested my fathers car I asked him what milage he on trip up, he said 20 mpg. We filled tank and immediatly got on highway and took a 80 mile trip got off highway drove afew miles though town to our destination. Then we left on got back on highway and drove 80 miles back. When we got near home I tested response of engine and I could feel stronger acceleration when goosing it a few times. We got off highway went gas station and filled up and calculated milage. We used 5.4 gal. and went 160 miles.
As with any car driving responsibly by not standing on accelerator, jack rabbit starts, hard stops will enhance milage. You will experience quicker response and more torque and horsepower. The trade off will be use more horsepower get less milage, but you will always do better in either situation with magnets on.
I hope this will work for you as it has worked for me. i seem to find new applications everyday for magnets. good luck and if you have any questions i will try and answer them. Don