Whenever you're just cruising down the road, maybe like a neighborhood street, how fast are you going in your Chevelle? My car seems to go about 5-10 if I don't give it gas and just pop it into gear from park, but if I give it a touch of gas or get it up to a speed then let off, it won't idle down past 25 mph. I just thought that this was strange. My engine is a 350 but at the same time I had a '94 truck with a 350 in it who would slow down to 10-15 (5 if the road was long enough) when just idling down the road. Thanks.

It depends on the gear ratio, resisitance of the vehicle (tires, drivetrain), converter and transcondition, brakes, and of course, the engine (idle speed, power and state of tune)...

Do you have a tach? If so, what RPM is 25? Plus, once you get going, it will likely shift to the next gear (for an automatic).

It also takes more to get the car moving, which might be another reason why it will go 5-10 by itself, but only come back to 25 after its moving... So much easier to keep it moving...

My old Chevelle in high school, totally stock Powerglide and converter, with ~2.73 or 3.08 gears would idle low enough that when already stopped, I could take my foot off the brake and the car wouldn't move...