Don’t underestimate the importance of Mazda’s 2.2 engine cooling system. You may use code of motor R2 and volume figure of 2.2 or just tell the 2002 year of production to buy liquid. For sufficient use of Mazda E Series you need to use suitable antifreeze. It’s important to use 9 liters of coolant which has Red color. In other way 1988 E Series won’t be used quite long and efficiently.
So better use Mazda’s advice for servicing 1991 E Series. Providing you keep the rules 2.2 motor installed in E Series of 1989 year will be long lasting. A lot of R203 motors are used long in Mazda cars but only with good service. Better buy 9 liters of good antifreeze in Red color.