1988 Subaru GL wagon single point fuel injection:

 

So I have been losing coolant recently from my car. This only seems to happen on longer trips and not like 20-30 min drives. The entire reserve bottle will be gone by the time I turn off my car. There is coolant on the skid plate and back by the passenger axle. These are coolant drips and not large amounts of coolant in those areas. There is some coolant around the timing belt cover area. There was also some steam coming off of the engine at one point that I assumed was burning coolant and that was around the intake maniflold and throttle body. There was no leakage on the water pump weep hole that I could see. There are no visible leaks on any of the hoses. Temperature gauge stays about a little under half and it has never overheated. Heater also does not blow really hot.

 

Any ideas on what this could be? Thanks for any suggestions, Kyle.

Could be intake manifold gaskets leaking into the intake. Also the gasket under the throttle body. It is odd in my experience that the recovery bottle level is dropping - unless you wait until the engine is cold

check the weep hole on the water pump, as it can drip down to the Tbelt area from there. Also check the coolant hose that warms up the intake. I had a mystery thirsty EA82 and i finally found it by accident. all the coolant would evaporate off the top of the block and leave no evidence.

Yeah, that pesky little hose off top of engine to the T-stat housing.

 

Coolant leak there will cover top of engine and look like it's coming from intake gaskets.

Weep holes in the head at the sparkplug recesses let it run down both front and back of engine.

Keep in mind that hose leaks can seal when the engine is off or at idle. Park the car and start the engine. Open the hood and manually rev the engine by manipulating the throttle cable. Give it a good high sustained rev to force any leak. Watch for small streams of coolant from the small hose in the side of T-Stat or any of the radiator hoses.  A slit leak can self close and not drip at idle speeds, however at higher revs the coolant pressure increases and the leak opens up.