[HyundaiElantra]

Hello everyone. I have a 2000 Hyundai Elantra that i have owned for several years. I have tried a couple different mods over the years to play with fuel economy. I built a grill block from plexi glass but my car could not maintain a low enough engine temp so i had to remove it (no notable fuel savings while it was installed). I have tried warm air intake and cold ram air intake (noticeable power changes but no fuel econ change). I bought a Scan Guage but found that my normal driving style was already about as fuel efficient as it could be. I have toyed with the idea of deactivating two cylinders but in previous attempts on an older Hyundai fuel econ stayed about the same. (all I did was run a switch to two fuel injectors and turned em off while cruising at highway speeds). I have just installed a "restricter plate" just before the throttle plate with the theory that it will force my throttle plate to be open just a little more at hwy speeds reducing the sucking force on the engine, I have no faith in this working but I will have real numbers soon. My car right now fully stock *(before the plate) gets between 35-38 highway (it is only rated to 30 epa). I want to see 40 but can never quite get there. Any ideas?