You can use either one, and they are miscible. The big determiner for most people is climate, Dot3 is much less hygrophilic (moisture-loving) than Dot4. So if you live in an area with very high humidity like the southeast US, Dot3 is probably the right choice. However, Dot4 has higher wet and dry boiling points and outperforms Dot3 in most other ways, so if you live in an area where humidity isn't a big issue, Dot4 is usually the right choice. I work in central Arkansas where humidity is an issue but some of our customers come from the very-hilly Ozarks north of here. So for most of my customers I recommend Dot3, but for the few who live in the hills or routinely summer there, I always recommend Dot4.

 

Excellent!
How much do I need for the flush?Thank you.

 

They don't list a capacity, but for a power flush or bleed flush have at least 16 oz on hand. For a spill and fill with a turkey baster, a regular 12 oz can will do it twice. Flushing the system routinely is overkill, I don't do that even with my wife's beloved Altima. I power flush it at 60K's and do spill and fills in between at 15~20K.

 

Totally agree with the overkill. But the dealer says it's scheduled service per OM and therefore required to keep powertrain lifetime. At $220.00..... I am doing it myself.
I got two trucks over 20 years old, I only flush at brake service pads/rotors since I am already there. Both doing just fine.
And besides, how fresh is the fluid in the machine at the dealership anyway. Are they really concerned about the moisture?

Many thanks

 

I dunno about your dealership, but in ours the power flusher tank only holds spent fluid. You top the reservoir out of a fresh bottle as the old stuff sucks down. Vis the warranty, the only thing they can possibly check is the receipt. Buy a large can but don't use all of it, just use enough for a basting.

 

BTW, Dot3 is what you get from the factory. Dot4 is optional.

 

Fluid flushes are some of the best things you can do. Brake flushes really cause a positive impact. Provided the shop flushes it. With my mitsu I was doing a drain and fill on my CVT every other oil change