I've read up in the manual and in various threads about coolant, but I have a few questions that need clarification. First, I have a one gallon jug of yellow extended life Prestone af/coolant. It does contain ethylene glycol, but a member in another thread said to avoid yellow/orange based af/coolants. This stuff has a 265 degrees fahrenheit (at 50/50 dilution) boilover rating which should be plenty for an n/a 8 right? Also, concerning the second drainage bolt discussed in another thread, why is it not in the manual as necessary for a coolant change? What are the benefits of flushing/draining the coolant using both bolts?

 

Don't rely on color, just make sure the right spec coolant is used.

 

if you just want to do a simple coolant change, then just drain it at the radiator. if you going to change the coolant to evans then you need to drain it from both places.
the shop manual don't have that information, may be because the drain on the engin block is for engin swap, not coolant change.

 

Whats so bad about ethylene glycol ? besides it might melt the rubber ?

I read saw the extended life one at pepboys. it seems to be good but, isnt that the higher the boiling point the better ? (Prestone is a pretty good brand, it should be ok right ?)

 

Ethylene glycol is what the owner's manual recommends for coolant/af so there is nothing bad about it. My question was that people said only to get the blue (or green i can't remember) colored liquid and I wanted to know if this Prestone yellow stuff was ok. I guess the boiling point of 265 degrees is adequate since no one has said otherwise.

 

You cant really tell what kind of stuff it has by just looking at the color.

So I guess its good.

so I guess Im going to buy some and flush my Coolant later.