On a Subaru 2.2 or 2.5 N.A. under normal hot weather driving what should the water temps run at in Fahrenheit’s, what is normal operating temp range ?

 

Also what is the correct temp thermostat to use?

 

I'm considering converting to a Turbo. Do Turbo’s run hotter, if so at what temps?

 

Thanks

The factory thermo is labeled: 78*C, which is 172*F. Most folks that run a performance setup use the Zerosports 71*C / 160*F aftermarket unit. The Zerosports is a real Fuji (FHI) part which is an important distinction. DON'T use anything except a Fuji part.

 

Subaru cooling systems place the thermo at the water inlet as opposed to the outlet like most other arrangements. I'm not sure why, so I'll just assume it's a better way to do it.

 

Maybe someone else can chime in as to why ...I'm curious.

The factory thermo is labeled: 78*C, which is 172*F. Most folks that run a performance setup use the Zerosports 71*C / 160*F aftermarket unit. The Zerosports is a real Fuji (FHI) part which is an important distinction. DON'T use anything except a Fuji part.

 

Subaru cooling systems place the thermo at the water inlet as opposed to the outlet like most other arrangements. I'm not sure why, so I'll just assume it's a better way to do it.

 

Maybe someone else can chime in as to why ...I'm curious.

 

But what is the normal engine operating temp for a 2.2 or 2.5. Is 190-200 normal for hot weather driving?

Those temps sound about normal to me.

But what is the normal engine operating temp for a 2.2 or 2.5. Is 190-200 normal for hot weather driving?

I've never measured it, so I don't really know, but here's some book data:

 

My '02 2.5 manual lists normal discharge temp as 185*F.

 

It lists beginning-to-open thermo temp as 173*F, and full-open temp as 196*F for both turbo & non-turbo.

 

It indicates primary fan on-temp as 203*F for the non-turbo and 205*F for the turbo.

 

That should at least give you some indication of the range where Subaru is trying to keep the coolant temp.

 

A turbo motor of a given displacement will generate more thermal energy than an identical displacement N/A motor since it's burning more fuel and air, so the radiator ideally should be of a larger capacity.