My engine with a 130K has only seen conventional for the past 10 years. I plan to switch to Mobil 1 synthetic this weekend. Do I need to use a blend first, or just go straight to syn? How many miles should I expect to get between changes if 90% of my driving is highway (100 miles/daily).

 

Skip the blend, go right for the good stuff. You should be able to get 7500 miles easy out of Mobil1 with 90 percent highway miles.

 

short of a lab test, is there a way to determine when one should change their oil?

 

Its recommended about every 3k-5k miles. Dude honestly your over analyzing this. Just switch the oil, not that big of a deal...

 

I agree...I tend to be OCD about stuff.

 

Just make sure you get the plug bolt nice and tight when you switch over. Synthetic will leak through smaller spaces than conventional will.

 

you can do more then 3-5k with synthetic maybe im wrong.

 

I really don't know for sure, I just switched to synthetic about 2 weeks ago.

sfazngiants says synthetic can go 7.5k here: https://www.hondacivicforum.com/foru...ad.php?t=82812

From what I've seen, he knows what he's doing. I'd trust him

 

we use synthetic and change it about every 3k miles. just make the switch, you'll feel better

 

comfirmed with trustdestruction