I finally did it! After a ton of post and research I finally got myself a 92 740! It will need a bit of cleaning before I snap some photos for here though

But, I do have a few questions.. The previous owner ran only Premium gas. Now, I know that is not a requirement, but would it be bad to just switch to regular right away after running premium for so long? For example: I ran Premium to fill up on the way home because it already had about 1/4 tank of premium and wasn't sure if mixing would throw off the timing and/or gas gage.

After a couple hundred miles, I'm near empty. Should I slowly work myself down to regular gas by putting a tank of midgrade in it next, running it to E and then put regular in? This way the engine has time to get ''use'' to the lower grade gas?

 

Your car is build to run on regular gas. You may change right away without doing any damage.

 

Yeah, I figured it would be okay. Just wasn't sure if I should slowly change to regular or just do it right away.

 

if its a turbo, it prefers premium, and will run with degraded performance with regular gas. probably won't matter if you just putt around, but if you're driving in the mountains, especially in hot weather, you'll notice the engine starting to ping/crackle, then retard. a non-turbo will burn regular US pump gas just fine.

the $0.20/g spread between 87 and 91 just doesn't seem as significant with gasoline in the upper $3/G range as it did when gas was $1/G or whatever.


as far as changing grades, nah, just put whatever in the tank, you don't have to blend. the engine will adapt quite quickly, a matter of minutes at most.