Aftermarket Coolant Mixing??
 

Quick question. Can I use Preston's Predeluted Longer Engine Life Coolant in my twin? I just checked my coolant level and it turns out its below the "low" marker. The tank is pretty much bone dry and I don't know how long I've been driving it like this. I've looked over some threads but I haven't found a definitive answer other than that it will decrease the life cycle of the coolant.

You can, but you'll reduce the life of the coolant. Best to use OEM Subaru/Toyota Blue.

It's supposed to be good for 11 years.

If you didn't lose it to leakage, just buy a new radiator cap. Most likely you have a slow leak there. The radiator cap can be considered a wear item. When you remove the old one, look at the fluid level at the neck. If it's not completely full, top it off with distilled water before installing the new cap.

Then add some distilled water to the expansion reservoir.

You're just replacing what boiled off because the old cap wasn't maintaining system pressure. If it continues, assume you have a leak somewhere else.

Awesome thanks for your help guys! I'll try your method Ultramaroon, to be losing that much coolant, there's gotta be a leak somewhere. @N1rve @Ultramaroon

I hear you but if you don't smell antifreeze in the engine bay or have any puddles, it's not a liquid leak.

If the cap has even the tiniest leak, pressure does not build. Without the high pressure, the water will simmer off invisibly so that each time the engine cools down, a little more fluid is sucked out of the expansion tank. Eventually it sucks dry and you start developing an air gap in the closed part of the system. This scenario is really really common.

You only add distilled water because the antifreeze itself does not boil off.

We can use 50/50 anti freeze by itself right? Like this?

http://scooters4life.com/shop/images...3_pri_larg.jpg

Read post #2

Kinda answers the question. So 50/50 will work it just will need to be re-filled more often I gather.

50/50 can be added to replace lost solution due to a liquid leak or you've otherwise drained the coolant from the engine.

Do not use it to replace loss due to evaporation. If you have a shitty radiator cap and the fluid level in your reservoir drops, you are only losing water.

You'll need to perform more coolant flushes if you follow the manual. You won't necessarily top off more often.

What good does it do to have coolant that is good for 11 years? Is there anyone here who believes that water pumps, thermostats, radiators and other coolant parts will last that long without requiring replacement and flushing of the cooling system anyway?

The people who engineered the car/wrote the manual?

Yes but probably not yours.

Nobody know's the car better than the manufacturer. However you can use different types of coolant other than just the one the manual states. You want to stick with the same color ofc unless you do a system flush.
@Ultramaroon knows what he is talking about, look at your radiator cap or reservoir cap for small leaks, even apply a pressure tester if you cannot find the leak. In theory, metal on metal parts should never wear out as long as the proper lubrication is applied. (This means regular maintenance and services, and checking fluid levels and contamination regularly.)