Good day eh! I was reading in my manual that I should put premeuim gas in my 06 2.4L Cobalt, do I really have to? and if I don't will it affect my motor? Thanks

 

Yes it is mandatory,so says the owner's manual, your car will run ok on regular fuel, but may knock and have slower acceleration. Just got my new ss sedan- blk 5 spd full load except leather/ onstar love it! will post pics soon

 

on my 2.4 ive done it both ways... if you werent paying attention, you may not notice the difference, but it will slightly knock and your power is a bit less. it will run though.

 

i wonder why they would say it's mandatory to run premium gas on the 2.4l but you can run as low as 87 on the SS/SC with the downfall of a little acceleration. But if your car is knocking u better bump up to the next octane level. knocking is not good

 

ya I've never noticed a noise etc yet but its break in time not drag race time..thanks everyone!!!