Hi !!
It seems hard to find any decent info about the Ultron..
Esso pages tell only :
"The Esso range of engine oils is led by the fully-synthetic Esso Ultron. It was developed to meet the ever-increasing demands of the modern engine. "
and Exxon Mobil Chemicals :
"
The engine oil market is the largest share of the automotive segment, which represents 50% of the worldwide demand for lubricants. Engine oils fall into three categories:
Main Applications
Passenger-car engine oil, heavy- duty engine oil, small engines (both 2 and 4 Stroke)
Specifications
API, ACEA and specific OEM’s, i.e. VW, MB for PCEO and HDEO, i.e. MB, Scania, Volvo, MAN; API, TCW, ISO and JASO for small engines
Base Stock Quality
Synthetic, partly synthetic, mineral
In recent years, synthetic oils have become more and more popular with consumers who enjoy their performance benefits, and also with OEMs who continuously recommend high-quality lubricants for their engines.
Fully synthetic engine oils are based mainly on synthetic base fluids such as low viscosity PAO, which represent up to 75% of a formulation and esters which can represent up to 20% of a formulation. The remainder of a formulation is the additive system which includes oxidation inhibitors, extreme pressure/antiwear agents, corrosion inhibitors, dispersants/detergents, pour-point depressants and viscosity index improvers.
"
and
"
ExxonMobil Chemical Synthetic Oils Deliver:
Extended service life
Higher output and increased acceleration by reduction of engine friction
Reduced engine wear and emissions
Superior performance in extreme weather conditions, thereby extending engine life
Faster lubrication of critical engine parts during start-up
Improved resistance to viscosity breakdown
Reduced oil consumption
Our PAO and ester synthetic base fluids also assist formulators in upgrading their current mineral oil formulations in order to pass the new, challenging specifications such as GF-3 (strengthen volatility specification) for PCEO and PC-7 (Mack T8 test) for HDEO. They also assist researchers in formulating ultimate lubricants to meet OEM’s extended oil drain interval challenges such as VW503-506 (OW30 meeting T4 test requirements), BMW (M44 test) and MB VSS2000.
"
So it seems that the oil is probably based on SHF41 PAO-stuff ..
And 'Race Proven' for Turbo Steve ;-)
http://www.exxonmobil.com/news/publications/c_winter00_lamp/c_racing_team.html
BTW.. Ultron outperformed Mobil 1
(and also Sell Helix Ultra , Cantrol Formula SLX etc.)