Hi everyone!, lots of new "faces" in here, I'm a semi retired member who still drive the same car I bought new in 92 (RSV8) for years the MPG has been very bad 13/14 in light traffic, never payed attention since car run like is no tomorrow n i like it that way if you know what i mean..for the last 6 months my daughter is the solely driver of the car just driving to school n back slowly in hot weather (90's) with a 170 thermostat which i think will rule out the possibility of running cold..maybe, maibe not..not sure, the thing is with daughter driving still got 13/14, no error here I still pay for gas LOL, no codes, any clues ?


Have you shared the left line today?

 

Sounds like you may need a tune-up.
Check your wires, plugs (re-gap if necessary), timing, air filter
Wouldn't hurt to grab a new O2 sensor

You know the drill.

 

\

Tune up? car start n idle fine n fly down the road with no issues

bad 02 sensor will trow a code right?

 

That's what I thought. Regapping my plugs brought back 2 mpg on my car.

A bad O2 will set a code but not a dying O2.

 

just because it sounds fine and does not shake in the motor mounts at idle does not always mean that its running as best it can. Plug wires, caps, rotors, and plugs all have a relatively short life span due to the high voltage and current in an ignition system. If you were to graph the performance of a standard plug, with output energy on the y axis and time on the x, it would start off high, decline quickly to a plateau for about a year, then steadily decline from there to the point of minimal combustion. Even with performance ignition components, I would still suggest a full tune up every year for daily drivers, and every 15,000 miles for that beautiful sunday (or saturday night) driver. This will help keep your fuel economy steady, as will keeping all your filters (dont forget the fuel filter) clean. Hope this helps,