If reflector is bad in fog-light of Cherokee 5.2, buy only recommended shape for 1994 year cars. For 2008 model year cars and vehicles with engine code ESF producer used special bulb dimensions. Base type BA15S is used in Cherokee of these modifications. It’s impossible for Jeep cars to install other dimensions than recommended for 4.0 motor vehicles. Nominal power of it is 21 W and optimal voltage is usual – at 12 V. It’s quite important for Jeep Cherokee drivers to ensure normal fog lights work.
A lot of light bulbs types for Jeep Cherokee are offered on the market. Capacity of simple 21 W lamps with base BA15S might be even doubled. In Cherokee reflecting panels might be darkened with lamps of more than 12 V.
Note that BA15S base lamps might have real output at more than 21 W. You must prudently place 12 V bulb into Jeep’s fog optics. But anyway check that fog bulb in Jeep Cherokee 6.1 is of high quality.