yes they are switching the blend, i have given up on fuel economy, the us government requires that all gas have a minimum of 10% ethanol content, and idgaf who anyone talks too ethanol is the worst thing you can try to burn in your engine, not only is it bad for components but by volume it yields less energy than gasoline, in other words in order to get the same power out of an engine that runs on gas the same engine burning ethanol would have to burn almost 2 times the amount of fuel. the fuel additives going into gas at terminals and refineries does play a major role, stick to good quality gas, the only companys i purchase from are exxonmobil and chevron, are there other decent gas stations? yes. but i reccommend those 2. and now companies will be forced by regulation to up the ethanol content to 15%. the best thing you can do is take care of your engine with good quality fluids, most people talk about oil and antifreeze and overlook fuel as a fluid. as far as off the shelf additives here are the good ones: chevron techron super concentrate fuel system cleaner, BG 44K fuel system cleaner (not available in stores but most dealerships will sell it to you as a part), BG MOA (motor oil additive), lucas upper cylinder lubricant with injector cleaner (increases fuel lubricity), lucas ethanol safe guard, star tron enzyme, and k-100 additive (those last 3 fight the negative effects of ethanol). let me be perfectly clear though: I AM NOT SAYING THAT ANY OF THESE PRODUCTS WILL MAGICALLY INCREASE YOUR FUEL MILEAGE. THEY ARE NOT SNAKE OILS. taking care of your jeep is how you will get the best performance out of it, you wouldnt buy a thouroughbred race horse and feed it twinkies would you?
