I have used SWEPCO in transmissions and rears since 1986 in all client and race cars. Never had a gear oil related failure in anything. Never had any oil on the ground issues like most synthetics.
I believe I posted else where on the site my experiences and other relavent information out this amazing product. For a street vehicle you will probably never have to change your oil again since SWEPCO's recommended service time for change is 10,000 hrs. They offer an oil analysis for their product recommended test time is every 3 years.
To check out more go to
www.swepcousa.com.