optimizing title meta tag

[iWebTrack]

Hello -
Currently I am working on optimizing title pages on one of our sites, and I wanted to know roughly how many times I can use the keyword in the title page, like if I do title tag with 60 characters can I say for example:
"car parts | oem car parts | online oem car parts"

Wouldn't that be overstuffing with keywords?
Also, is it better to use commas or | symbol in the title?
Please let me know your opinion, every advice is appreciated.
Have a nice day

[goodroi]

the way search engines value the keyword in title tags is alot more sophisticated than it was 10 years ago. 10 years ago your title tag would have been fine. in the current environment i would not use it.

here are two concepts you may want to think about:

placement of keywords - forget about how often the keyword appears. the search engines are much more sophisticated than that. they are taking into account in what order the keyword appears and what words surround it.

usage data - having a title tag with poor usability aka not being attractive to real users is bad. search engines pay attention to how often your site is clicked on in the serps. if your title tag does not attract users to click on then your rankings likely will suffer. avoid looking too spammy by stuffing keywords into the title tag.