Engine oil monitoring system having an in-vehicle display of the current status of the oil

An oil monitoring system for an internal combustion engine mounted in a vehicle, said engine having a rotary output member and an oil sump storing oil for lubricating said engine, said system comprising;

• means for generating tachometer pulse increments corresponding to the rotation of said rotary output member, said tachometer pulse increments being proportional to the number of revolutions of said rotary output member;
• means for generating a weighting factor as a function of the temperature of said oil in said oil sump;
• an oil sensor for generating an oil level signal having a value indicative of the level of said oil in said oil sump;
• means for multiplying said weighting factor by a predetermined quantity in response to said oil level signal having a value signifying the level of said oil in said oil sump is below a predetermined level to generate a corrected weight factor;
• means for multiplying said tachometer pulse increments by said corrected weighting factor to generate a weighted tachometer pulse increment;
• means for storing a remaining percent tachometer oil life indicative of the remaining number of revolutions of said rotary output member before said oil is to be changed;
• means for detecting the generation of a predetermined number of weighted tachometer pulse increments to decrement said remaining percent tachometer oil life by a first preselected percentage;
• means for storing a remaining percent time oil life indicative of the actual time remaining before said oil is to be changed;
• means for detecting the passing of a predetermined time interval to decrement said remaining percent time oil life by a second preselected percentage;
• means for storing a remaining percent odometer oil life indicative of the number of miles remaining to be driven by said vehicle before said oil is to be changed;
• means for detecting each time said vehicle has been driven a predetermined distance to decrement said remaining percent odometer oil life by a third preselected percentage;
• means for selecting the smallest of said remaining percent tachometer oil life, said remaining percent time oil life and said remaining percent odometer oil life to generate a smallest remaining percent oil life;
• an in-vehicle display for generating a visualdisplay;
• and
• first means for activating said in-vehicle display in response to said smallest remaining percent oil life time being decremented to zero to display a first message signifying it is time to change the oil.

An oil monitoring system for an internal combustion engine mounted in a vehicle, said engine having a rotary output member and an oil sump storing oil for lubricating said engine, said system comprising:

• means for generating tachometer pulse increments corresponding to the rotation of said rotary output member, said tachometer pulse increments being proportional to the number of revolutions of said rotary output member;
• means for generating a weighting factor as a function of the temperature of said oil in said oil sump;
• an oil sensor for generating an oil level signal having a value indicative of the level of said oil in said oil sump;
• means for multiplying said weighting factor by a predetermined quantity in response to said oil level signal having a value signifying the level of said oil in said oil sump is below a predetermined level to generate a corrected weight factor;
• means for multiplying said tachometer pulse increments by said corrected weighting factor to generate a weighted tachometer pulse increment;
• means for storing a remaining percent tachometer oil life indicative of the remaining number of revolutions of said rotary output member before said oil is to be changed;
• means for detecting the generation of a predetermined number of weighted tachometer pulse increments to decrement said remaining percent tachometer oil life by a first preselected percentage;
• means for storing a remaining percent time oil life indicative of the actual time remaining before said oil is to be changed;
• means for detecting the passing of a predetermined mime interval to decrement said remaining percent time oil life by a second preselected percentage;
• means for storing a remaining percent odometer oil life indicative of the number of miles remaining to be driven by said vehicle before said oil is to be changed;
• means for detecting each time said vehicle has been driven a predetermined distance to decrement said remaining percent odometer oil life by a third preselected percentage;
• means for selecting the smallest of said remaining percent tachometer oil life, said remaining percent time oil life and said remaining percent odometer oil life to generate a smallest remaining percent oil life;
• an in-vehicle display for generating a visual display;
• means for activating said in-vehicle display to display said smallest remaining percent oil life;
• and
• a reset switch actuable from an "off" state to an "on" state to signify the oil in said engine has been changed, said reset switch in said "on" state resetting said remaining percent tachometer oil life, said remaining percent time oil life and said remaining percent odometer oil life to 100 percent.