*Look Close AT This Fram Filter * I would like to tell you that some magic bottle of stuff you could dump in your cars crank case would get you 1 or 2 miles per gal better mileage . I have been involved in test with different kinds of oil products mostly with industrial equipment that runs 24 - 7 ,and will oil additives really get you better mpg ? That can be hard to answer ,but lets look at a big problem with saying something else other than standard oil dumped in your engines  can make a difference not just lubricate , To make things simple think of your engine as a big one cylinder engine ,That is going to do all the work needed to move your Car or Truck down the road at lets say 50 miles per hour with that piston going up and down in that single cylinder at a rate of 2000 strokes in just one minute or 2000 RPM . The engine is linked solid to a gearbox and rear axle "right now" solid and the axle is turning the rear wheel at a rate of lets say 4/11 or every time the piston goes up and down 11 times the rear wheel and tire makes 4 full rotations .Every other time(that is 5 and 1/2 times) the piston goes up and down its going to suck in gas & air (and it sucks in the same amount of air and vaporized gas on every stroke or it will not push the car and the car will start to slow) .This is a Fixed rate and oil will not change that rate. Oil only acts as a agent to make the bearings in the moving parts last (and other polished bearing surfaces ) ,with out oil the car would still run but not for vary long .Advertising would have you think that Oil is some kind of "super bearing "that could make the piston slow down and still do the same amount of work some how ,Its not going to happen that way. Nothing you dump in your crank case will change the ratio between the piston moving and the rear wheel turning ,Now what is vary important is keeping that piston moving real nice over time and exposed to a lot of heat .If you over heat the bearings you will not get vary good gas milage for long (The engine will lock up and stop and then no mpg) . So now we are faced with a problem , Oil will keep the bearings from over heating as well as keep them clean .Oil is not a Bearing it is just lubrication THAT IS it is a coolant, a cleaner, and something like a super fine polishing compound, and it also fills voids and creates high pressure spots (floats a moving part ) .You could run your engine on cold water it is a solvent as well as a coolant,and it will fill voids but water can,t stand the heat so watered bearings would not last long and the pump would need to go, to hundreds of PSI for water to work in the first place "Note if you could run very high oil pressure you might be able to float the Crank ,Rods, and Cam on oil pressure ,at that point the oil would act indeed as a bearing surface ,but pressure would top 75 psi or more  to do that ,and that would trade off BHP power to run the oil pump so no gain might be seen.  Standard engine oils can only take so much heat and dirt before they brake down and turn into something other then oil like a block of hard carbon or vary thick sludge "also known as grinding compound". Enter Synthetic oil .the advantage of this type is ,it can stand a lot more heat and will not brake down to carbon as fast as standard out of the ground petro oil . Hard partials of carbon and iron and aluminum oxide and oil (or Dirt and Oil ) is something called grinding compound ,Carbon is what diamonds are made of . and if you have that in your engine its not going to run vary long ( thats what your oil filter is for ) . OK now maybe you can see some of the issues . If a engine is to tight and its hard for the piston to move, no oil on earth as well as additives dumped in the oil will help it get good mileage ( A vary tight engine will need to burn a little more fuel just to overcome being tight" Thats a Tight Engine")and if the bearings are to loose they will not hold a little oil so it can do its job (That is a cleaner and coolant as well as filling vary small voids on bear surfaces so the bearings will last ) and the engine may burn some of that oil ,reducing power and then bad mpg , one again no oil additive  on earth can fix a vary loose engine ,also one issue is ,that a some what loose engine will not work vary hard to turn its self  may get good milage but the bearings will over heat and burn away fast ,engine then stops your done .No additive or super oil can help that type of issue either.A engine and drive train that is built just right ,not to tight of fit together and not to loose and has high oil pressure so it can float the crank and  rod ends as well as the cam on the oil will get vary good fuel mileage and hold up well . Standard oils already have lots of additives to help them last or not burn up and Synthetics have even more and last longer and stand up to lots more heat ,in the long run it will be vary hard to see mileage gains with any over priced so called super oil and even harder to see a gain by dumping in more additives (and some additives are just cheap mineral oil with color added to make you think they are something they are not ). Finally if a engine turns on its bearing surfaces with vary little resistance and with great precision,and use all the right alloys , it should get vary good milage .Problem ! todays workmanship is done as cheap as it can be done,and the lowest quality bearing surfaces are used ,and the buyer is the inspector (robots inspect nothing ), Proper brake in driving is now a must (most engines are built a little tight so they will make it to the end of the warrantee .Then at the end of the warrantee may be vary loose and ready to send to the junk yard or even sooner ) . I can not advise the use of any oil additive for a magic mileage fix ,but  I do run Synthetic oils ,I have tuned my engine to run vary hot and I don't want it to lock up running hot ,Syn oils can last a lot longer under a lot more heat applied about 50 degrees more then out of the ground petro stuff  .I also use Quality oil filters like Wixs, K&N and NAPA gold and change filters when needed ( I never use FRAM ,Lee or Purolator oil filters NEVER ) . Last word a Twin Race filter set up will reduce stress on the pump and you could see a mileage gain  (vary small) and the oil will last much longer . Hotter engines burn the fuel better that is another story.and I do have a Bearing coating additive but it cost a lot , more over ,no one would like the price. Over $600 a gal but it makes a notable difference maybe as much as 1/2 mpg it has a little gold alloy  in it and is not for sale to the general public can't tell you how its made  . I have tested almost all the other dump in the engine stuff and have never noted any improvement in mileage although some of that junk out their has done some damage to things like seals ,rings , and even plugged up the oil pump and that was a real disaster. Standard Oils are OK change often as needed and don't overheat the engine , Synthetic Blend Oils do last longer but still have a hard time with Heat , Good Brake in oil and good in the cold areas , Full Synthetic Oils can really stand up to a lot of were and heat but still filter changes are a must!. And as for Additives all the Oils on the market have them and more is not always better . Just because some NASCAR  driver has a big STP or something like that  on the top of the Race car dose not mean he dumped the stuff in the engine .And more than likely did not . And you Might vote the Big OIL Guys out of office that may help with mileage also , Press the button and vote on this good or bad ,Yes and No. I would like to know if you got my drift on it , and change your own oil its cheaper that way . Almost all the bottles of dump in the crank case additive junk will do more harm than good or little to nothing at all at best and then you have been scammed "that junk is not cheap also" ! Extra Additives may do more harm then good in some cases .All Engine oils have a mix of good additives and to much of a good thing can be bad .Final word Engine oils that are used in piston Aircraft engines are the finest ashless quality oils and will out proform all other types of petro oils for standard engines, If you loose a Aircraft engine due to bad oil you can't pull over to the side of the road and call a tow truck ,You crash ,and no one I know who flys would dump a QT. of magic teflon ,graphite , moly or top secret trash  into a aircraft engine . NEVER .If you know of a Oil additive that you have used and know beyond any dought that It works to save you fuel let me know ,so I can test it ! Something called ZDDP was removed from oil years ago due to ,it coated the catalytic converter inards in newer cars ,but you can buy this stuff and use it in pre air pollution cars ,but don't use more than 2 oz. ZDDP to 4 qts. of oil ,to much of a good thing can cause damage to any engine (years ago a lot of people lost engines with  problem oils .Engine oil makers put to much ZDDP or Other additives in the mix .ZDDP is a anti were additive and works well but to much will foul ring gaps and other engine parts *note A lot of good racing oils still have traces of ZDDP in their oils and if the oil is rated for the street its ZDDP amount is real small .Oil must be a fine ballance of Base oil stock and all types of Additives  . To finish up on fuel saver junk ,you might check to see if some screw ball item is approved for piston aircraft use ,if not you might want to stay far away from it (what ever it is ) You might just run Aircraft oil in your car ! One brand I have used is Airoshell 30wt ashless petro oil The thing about aircraft ,if the oil fouls the spark plug you can not just pull over to the side of the road "onece moreYou Crash" . And may The Gods help you save money at the pump !The High Treason of All of our governments Traders will NOT ! (The Front and THE Covert Grovernment included)! Their working for the Big oil guys and OPEC ! And they have demostrated for a long time their haterd and contempt for "WE THE PEOPLE" and we pay their way with outragous taxes ,and they have free Cars ,Oil ,Gas ,Offices,Staff , Mailing,Homes ,Electric,Personal Police Protection ,Health care ,Open end no pay back Charge Cards,Tax wrightoffs ,Part time jobs ,on oue time working for Hallaburton ,you name IT ,they get it all for Free "its all part of the Job !"  Update ** You CAN stop hear or read on  **Things I have tried that did not work for me or made things worse .Most Oil additives !, I have used all types of over advertised stuff in cars since I got my first car in 1965 ,worst of all something called CR2 did real damage and I had to repair a engine after it turned to small clumps of carbon coal looking stuff and locked up a oil pump . STP is ok to use as cheap assembley lube ,But Pro Assembley or cam lube (from rod shops)is safer to use . Tornado air spinners are not good ,race type Velocity stacks work well ,ram air a lot better at speeds over 35 mph.K&N Oiled Air filters are good ,most dry paper air filters are not so good , I realy hate Exxon Mobel for polluting our national coast line with oil spillage ,In spite of that Mobel 1 synthetic oils have been priced good and most Synthetic oils hold up better than Petro Stock oils .Amsoil might be another good oil due to the fact that they have been making Non petro oil longer than almost all the others combined "they should know what they are doing by now ". If you are running E85 fuel you should be carefull what oil you use . I would do a bit of oil resurch E85 will put a lot of water in your oil so your oil choice will need to be one that can suppend a lot of water in the oil ,Valvoline VR1 race oil was designed for top fuel cars "Alcohol" ,and also containes some ZDDP and is a ashless oil like aircraft oil ,seems like the best of all worlds if you don't trust Synthetic oils ,it should be a good oil if you run flex fuel E85 .DO NOT USE ANY MORE ADDITEVES WITH THIS OIL DAMAGE WILL OCCURE ! If you run E85 you should run a little RED LINE Lube for Alcohol fuel (in the fuel tank) ,in the fuel from time to time to block corrosion in the fuel system . Or run Reg GAS after a few fillings . AND DON'T TRUST FUEL SAVING SALES HIPE . Poorly made items can do more harm then good and in most cases you don't even get what you pay for or even close ! Best of Luck