Is it OK to put Mobil-1 5W30 synthetic oil in a 1993 civic with over 190,000 km (120,000 miles)? The car runs extremely well on Castrol GTX 5w30, but I am thinking of putting synthetic in it to protect the motor even more. The car doesn't burn or leak oil anywhere. My questions are:

1. Can it cause an oil leak to appear?
2. Can it cause the engine to start burning oil?
3. Is it worth the money?

Thanks.

 

I started putting synthetic in my high mileage car and it did show a minor leak and it did burn the oil pretty bad. IMHO I wouldn't, you generally want to stick with whatever you've been running in your car mostly. I put it in a civic that had 123,000 miles.

 

another question about this... if you have a little bit of burning oil would you recommend switching to non-synthetic, or putting in an oil additive or what?

Edit: I currently run Mobil 1 Full Synthetic

 

If you have a high mileage car, I do not suggest switching over. I did this on my old motor and it didn't work out too well, as leaking was an issue.

If you're burning oil, find out what is the cause, you should stick with synthetic.

 

what about additives? its a slight burn, i just wondered if there was a way that i could stop/slow down the process. i'm going to get rid of my car within the next few months (likely) so i'm not going to spend the $ for new piston rings at this time

 

From my experience and heard, additives aren't the best fix, but since you're saying it's a temp fix, I think that'd be a chance to take.

 

midwestgsr, how about using a high mileage engine oil?

 

lol, i just started a thread about that... (didn't want to vere too much off topic)

please list what you know about it in that thread... i would really appreciate it

 

sorry,,,i've got no experience with high mileage engine oils.

 

I had 92k miles on my 97 EX when I switch to Mobil1 10w-30 (used to use regular 5w-30).

My car used to not consume any noticeable amount within 5k miles. After switching, it now consumes about 1/2 qts every 5k miles.

I used to never VTEC before, but after studying more about my car and switching to full synth, I started revving more to 6k-ish to extract power I never used. I haven't recorded to be sure, but I think I burn more oil when I rev more, leading me to think that with gentle revving my car's first 80k miles, I might have stressed the piston rings a bit going into a rev range (due to rod stretch or whatever). Plus, the WOT needed for high revs probably cause more blow by than gentle times.

Anyways, before I switched, I read that sometimes the synthetic can dislodge caked up stuff that was previously helping to seal the engine better.

However, I LOOOVE the way synthetic feels. The engine runs smooth. And if you change your tranny fluid too, your car will feel like new.