More or less but not quite? A gauge actually tells you something about the problem. So a check engine light tells you SOMETHING is wrong, it could be a loose gap cap or slightly dirty exhaust or something that won’t effect the ability to operate the machine or cause damage. Using gauges you can often get a very good idea of how severe a problem is or even what is going on.
The oil pressure gauge was removed for a couple main reasons- but the biggest reason is… most people can’t read gauges and don’t understand machines. A functional oil pressure gauge tends to jump around. When you start a car the oil is “thick,” motor oil tends to become more viscous (thin) as it heats up. A cold engine means cold oil. So oil pressure will often read high. As the car warms up and you drive the oil approached the operating temperature and thins out some. Then oil pressure drops. Often quite a bit. Because of how most, especially analog oil pump systems work, as the rpm (engine rotation speed)…
Changes and gears change and how much throttle you are giving or the load on the engine (going up hills, rough terrain, etc etc..) the oil pressure gauge needle or value will change, sometimes rapidly. Dealerships and such had a lot of issues with people who believed their cars were broken or in danger of failure because of that. Likewise, especially on older cars, there can be subtle fluctuations in readings on the voltometer. Turning on head lights or running certain high load electrical devices like AC or aftermarket stereo equipment could cause fluctuations.
The gauges of course cost money to add to the cars for the manufacturers, and in most cases people didn’t use them or use them correctly.
As we went to OBD2 systems and complex computer controlled emissions, it became even less helpful to have such gauges as many of the most common problems would be issues with electronics themselves or emission equipment and slight variances from specifications in the operations of these..
.. systems. Modern cars tend to require special service tools and procedures and are much harder for the “DIY mechanic” to do all their work unless they have a host of often expensive and sometimes proprietary tools, and knowledge. As we moved into hybrids and electric cars it starts to become even less practical to service at home for the average “gear head” since not only are these cars mostly electronics components, but they run high voltage and can easily kill you if you try to service them without high voltage knowledge and proper tools and references. So largely there was a transition due to complexity where even if they gave you the means to know what was going on with the car- it probably wouldn’t be helpful and you almost certainly couldn’t fix it it yourself for the average person who could have possibly done a simple belt replacement etc. on an early or pre OBD2 car.
The other factor is also that many newer cars… they work weird. The CVT transmission is a great example. Constantly variable transmissions came out as a new technology to increase fuel mileage and decrease emissions. Most cars you’ll ever drive with a CVT don’t have a “true” CVT because the way a CVT shifts gears as designed tended to offput and scare consumers. They would run the RPM high and hold it there and people thought the units were broken when they were working as designed- they just work differently than people were used to.
Likewise, thanks to more sophisticated computers and the inclusion of solenoids and electronics in traditionally analog components like thermostats, there is much more control over these systems and they can be made to behave for optimal efficiency vs. their traditional and “natural” behavior. So a modern car might use the computer to force the thermostat and oil system to stay closed or near closed until the car reaches operating temperature or at…
Various points in operation as sensors detect operating conditions and decide temperatures need to be increased etc. for efficiency and emissions. Older thermostats and oil bypass systems tended to act fairly predictably. The thermostat would stop all or all but a small amount of coolant from circulating if the coolant was below a certain temperature. An analog component- usually a metal alloy piece and diaphragm, would trigger the opening of the thermostat when the temperature threshold was reached to allow coolant to flow. So when starting the car the coolant temp would be low and then begin to rise and then mostly stay fairly steady if you didn’t have any problems. In a newer car the temperature could fluctuate wildly and spike at times in ways that based on experience with traditional systems would imply a problem.
So there are a few reasons why they got rid of gauges on most cars. As a fun fact- many cars that have “gauges” don’t! The Mazda RX-8 is one example, it has an “oil pressure gauge” but all it is is a sensor that detects wether there is 0 or more than 0 oil pressure and the needle is just designed to move in a way that makes it look like it is doing something. Many cars don’t even bother to go that far and have a gauge that doesn’t even have an “on/off” sensor- there is no sensor and the gauge always behaves the same way no matter what and is either controlled by a clock spring that when energized makes the needle “creep” into position so it appears to be reading and going up as the cad gets warm, or the computer just controls the needle but not based on a parameter- just a routine to make it look like it is doing something. They did this largely because as we transitioned away from these gauges being common, many people were upset or uncomfortable.
So even if you have a “gauge,” it might not be functional at all! Also, even if you have a functional gauge… it might be completely inaccurate. Some cars were known for this issue with the coolant temperature especially. By the time the gauge registered enough temperature change to move the needle even a small amount over the normal temperature line, the engine would often have already suffered catastrophic failure.
The oil pressure gauge was removed for a couple main reasons- but the biggest reason is… most people can’t read gauges and don’t understand machines. A functional oil pressure gauge tends to jump around. When you start a car the oil is “thick,” motor oil tends to become more viscous (thin) as it heats up. A cold engine means cold oil. So oil pressure will often read high. As the car warms up and you drive the oil approached the operating temperature and thins out some. Then oil pressure drops. Often quite a bit. Because of how most, especially analog oil pump systems work, as the rpm (engine rotation speed)…
The gauges of course cost money to add to the cars for the manufacturers, and in most cases people didn’t use them or use them correctly.
As we went to OBD2 systems and complex computer controlled emissions, it became even less helpful to have such gauges as many of the most common problems would be issues with electronics themselves or emission equipment and slight variances from specifications in the operations of these..
Likewise, thanks to more sophisticated computers and the inclusion of solenoids and electronics in traditionally analog components like thermostats, there is much more control over these systems and they can be made to behave for optimal efficiency vs. their traditional and “natural” behavior. So a modern car might use the computer to force the thermostat and oil system to stay closed or near closed until the car reaches operating temperature or at…