I've had a OEM fuel economy gauge (vacuum gauge) in my car for a while. Usually the needle doesn't budge unless I'm driving on the highway up an incline.

I got my car serviced recently, which included repairs to the exhaust, new plugs, filters, oil, timing belt, radiator (old one had holes), water pump, & brake fluid. (Yes, it was quite 'spensive!)

Now the gauge is more active, with the needle often entering the red zone while driving on the same stretch of inclined-highway, whereas before the needle hardly budged.

Also, the engine seemed to hold onto vacuum much longer after the engine is shut off before the recent servicing. Even after five minutes, the vacuum gauge still isn't pointing to the red zone. Now the needle gets into the red zone in less than a minute.

Which is a more "normal" measurement of typical engine vacuum behavior? Am I losing too much vacuum while driving? Is there a vacuum leak somewhere?

I realize that this gauge is not as accurate as a true vacuum gauge, but it does indicate trends of engine vacuum, yes?

I haven't checked all of my vacuum lines to make sure none were damaged during the servicing.

Thanks.
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Mike F - 1984 244 DL - 224,000 miles - with Euro headlights and lots of gauges