Triumphrat

tacomaguy · 05-29-2009, 11:30 PM

Sorry for another oil question but I ran a search and didn't find an answer to my question. I have been running fully synthetic amsoil in my 96 T-bird for 2 years. However I have many quarts of 10-40 semi-synthetic castrol sitting around from the old days. I have always heard that once you run full synthetic you should stick with it. BUT those jugs are just sitting there and i don't ride the T-bird very hard (Have a Tiger for that).

So can I go back to semi-synth until I use up the old supply and then resume using fully synthetic?? (BTW- bike has 35,000 miles and runs great)

Thanks

Paul

denny · 05-29-2009, 11:58 PM

Is that semi synthetic MOTORCYCLE oil?
If it is Automotive oil with friction modifiers in it I would not use it in the bike.

Other than that, Well ymmv This is going to be a controversial subject.

tacomaguy · 05-30-2009, 10:44 AM

yes. The semi-synthetic oil is also motorcycle oil. I just decided to run the synthetic since everyone seemed to feel it increased engine life. But since I only put about 3000 miles a year on this and will be changing oil annually anyway, I thought I would use up the case of semi-synthetic I had before I went to the full synthetic. But now I would like to use up the old stuff as long as it wont hurt the engine to go back and forth. Bad idea? Or no big deal?

Paul

lovecuba · 05-30-2009, 08:02 PM

No worries. Did the same 20,000 odd miles ago and no problems. Also run the same semi-synth in the Sprint which does long, hard mileage, again, good as gold!

RandyRick · 05-31-2009, 01:32 AM

As long as you change the oil more often, and don't run at max rpm's all the time, you should be ok.

Here's a link to an oil forum..

http://www.bobistheoilguy.com/index....tpage&Itemid=1

ssevy · 06-01-2009, 01:27 PM

IMHO, the best thing to do with that old semi is to donate it to someone running an old Harley or Triumph, as they go through LOTS more oil than we do!

Seriously, the fully synthetic oil tends to clean as well as lubricate, which accounts for the nasty looking first oil change for those folks who have switched over from mineral based. Semi shouldn't produce as much sludge and crud as 100 percent mineral, but if I were going to be cheap (sorry, frugal) and use up the old stuff, I would alternate oil changes with the Amsoil. That way, your seals won't take a hit and start leaking (which would be rare), and any increase in deposits would be flushed out by the next Amsoil change. You can have your cake and eat it too!

ssevy · 06-01-2009, 05:24 PM

Sorry I forgot to mention an important point - quality of shifting. I found upon switching to Amsoil that it made for much smoother shifting than either Mobil 1 or Royal Purple motorcycle oils that I had previously used, so if you do go ahead and use the semi, make sure it doesn't make the shifting poor.

Mag00 · 06-03-2009, 07:27 AM

Modern-day oils are fully compatible. You can mix synthetic with semi-synthetic or even synthetic with traditional dino oil. You won't have any problems by switching to semi-synthetic oil.