This worked very well on my 1999 Jeep Cherokee 4.0. It was a direct replacement for the factory thermostat, which opens at a slightly lower temperature. So my jeep is right in the middle of the moderate pressure scale, delivers hot heat and appears to deliver better fuel economy. specific temperature range to work in the most efficient condition. If the car is running cool, it's also likely to use a lot more gas (and you're probably sucking). Don't believe the bullshit that lower temp raceβ¦