Re: Type of gas and whether to use lead substitute?

Posted by JeromeSolberg On 2022/11/18 2:37:44

"Why do new cars get away with 87 octane with 11:1 compression"

There are really 3 reasons:

1) Direct injection

2) Variable valve timing

3) Infinitely-variable ignition timing

All of them, in combination with computer control and knock sensors, allows the engine to run on the edge of knock all the time. In fact, many cars will detect and compensate for better or poorer gasoline - so you can get better performance with higher-grade gasoline (because of more advantageous timing), but the car will still run with lower-grade gasoline.