Make sure for the flushes that you use distilled water. It's less than a buck for a gallon at grocery store. You will find that once you drive and let it cool you will need to add about a quart of water (after it cools). I would still run more than a 30% solution because of corrosion and/or water pump lubrication. Not saying its necessary-that's just me. Then again I had a heater core go bad - so what do I knowhs thompson said:Well that seems easy. I've done it many of times with my other vehicles but i was told that when you do an SR20DE you will get air bubbles in its coolant system and you will screw the engine up. You gotta jack the front of the car up and open a plug somewhere on the block. Thats why i said f-it and let Nissan do it. I'll do the crap myself in another 20k miles. Thanks!