The new Yukon XL

[NMPastor]

Other issues/questions on the new 2001 Yukon XL SLT...108k

• 
  I've also got a 2005 Suburban...absolutely base. It's had non-synthetic in it three or four times in 238 k miles. My inclination would be to go synthetic in the new ride, but I don't know what's been in it. What are the risks?
  
  I'm hearing belt whine. Any way to tell if the alternator is going out other than failure? The battery light seems to take a while to go out when started up, but the gauge reads about 14 volts when running...just like it should.
  
  The parts lists indicate that there were two different designs for alternators on this vehicle. Is there any real difference between them, and how would I know which to buy?
  
  The Delco new alternator is now 145A, as opposed to the original 130A OEM. And problems with going with the higher amperage?

 

[Yukonboy2014]

1.) switching between non-synthetic and synthetic oils will do no harm. Personally, I've run synthetic oil in my Yukon once in its 242K life so far and it didn't do much more than conventional oil. So, I stuck with regular whatever the dealer puts in them now.
2.) Belt whine...Can you describe where in the belt system it is coming from, loudness, etc? Charging wise, for an '01 it should be putting out right at 14v. Maybe your battery is fixing to die?
3.) On the alternators, more amperage is better than less. No problems will occur, you will just have more power to spare if the need ever calls for it.

 

[NMPastor]

Synthetic oil

Virtually all oil changes have been done in my garage, by me or my son. I've always bought synthetic and what I think are the best filters I can find (using K&N for the last 4 years). After 238k it still uses no oil at all.

I don't know if it's because of what I have done, but it seems to be working.