Mashing at 150 VS 158, how will the beer be different?

Can anyone give me a mashing 101 explanation of what different mashing temperatures means to your beer?

I usually shoot for 151 +/- for my summer ales and around 158 on my dark brews.

Does the temp difference affect your final ABV% as well as “texture”?

Thanks.

EDIT: I should maybe explain that my objective is to brew a crisp lower alcohol beer for the summer.

I am probably not the best qualied to answer, but, My understanding is this. Lower temp, more fermentable sugars are extracted from the grain so more alcohol is produced. Higher temp, less fermentable sugars extracted so more dextrins which means more body.

Yeah???

Yes, it will effect both ABV and "texture."

What mash temp mostly determines is which enzymes will be most active during the conversion process. Depending on which enzymes are predominant, you will get a different balance of fermentable and unfermentable sugars.

Higher mash temps = more unfermentable sugars = higher FG = lower ABV = more "mouthfeel"

lower mash temps = more fermentable sugars = lower FG = higher ABV = drier finish (in the extreme, watery)

aha, much better stated.