[mor2bz]

this is my first post. don't know why i am interested in this stuff. i had a
toyota previa; it got the same mileage whether i dogged it or flogged it: 21 mpg on the highway.

My current Car is a 95 infiniti g20 with automatic trans. obd1 so i can't use one of the fancy gauges. i ran the tube for the gauge
with the hood release cable, then under the plastic wheel well liner then down and up into the eng. compartment.

the gauge reads 20-0 in driving. i figure that is about right as i am at
5000' and one is to lose an in. vacuum for every 1000' above sea level.

i am getting about 10" at idle in gear (unfortunately i have an automatic
trans.). that increase to about 14" in N.

usually for optimal economy one is to shift up at about 2k rpm. that sure doesn't appear to be the case with this car.

while cruising at 50 mph with the cruise control on flat ground i pull about
10" in overdrive. when i shift the button to go out of overdrive the vacuum
level increases to about 14". This is also true at 65 mph and to a lesser
extent even at 75 mph!

I am informed that the gear is not locked mechanically until one is in overdrive, and that one will always have hydraulic losses in any other gear.
so it seems that overdrive would be the way to go.

so it appears that these engines have less of a load on them when revving
high. I do not want to cruise in 3rd on acct. of engine noise and wear, but
it sure looks to me that in order to save gas one should almost avoid overdrive unless going very fast. I am very surprised.

comments?
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