本文章最後由 syk830 於 2013-6-30 13:19 編輯
samsong179 發表於 2013-6-26 14:00 ![請教機油濃度的高溫保護性5289]()
想不到這年頭還有人在信奉 ~ HTHS這種毫無意義的雞肋數據 ,
HTHS號稱高溫高剪切力黏度指數 , 卻跟抗剪切 ...
想不到這年頭還有人在信奉 ~ HTHS這種毫無意義的雞肋數據[size=12.800000190734863px]
看了這句話，實在無言，是真的雞肋還是雞排，我們來看看這段敘述：http://www.hddeo.com/hthsarticle.html#
High temperature high shear (HTHS) viscosity of engine oils is a critical property that relates to the fuel economy and durability of a running engine. The drivers behind lowering HTHS viscosity are new global governmental regulations to improve fuel economy (FE) and lower greenhouse gases (GHG) in new vehicles. Lower HTHS viscosity tends to improve FE and lower GHG but higher HTHS viscosity affords better wear protection so a careful balance must be found when formulating an engine oil. Sufficient HTHS viscosity is critical in preventing engine wear in the critical ring/liner interface area by maintaining a protective oil film between moving parts. One method used to measure HTHS viscosity is ASTM D4683. Oil is introduced between a rotor and a stator at the test temperature of 150°C. The rotor experiences a reactive torque to the oils resistance to flow (viscose friction) and this torque response level is used to determine the HTHS viscosity. HTHS viscosity by ASTM D4683 has been found to relate to the viscosity providing hydrodynamic lubrication in light duty and heavy duty engines. HTHS viscosity has also been found to relate to fuel economy. Think of the protective oil film as if you are trying to swim. If the film is too thick like molasses you can barely move and have to expend a lot of energy; too thin and you sink to the bottom. What you want is the right balance of support and ease of movement. The oil has to be thick enough to maintain separation of the critical moving parts but thin enough to allow for fuel efficient operation. A new heavy-duty engine oil category, PC-11, is currently under development. PC-11 may be split into two categories one with HTHS viscosity less than 3.5 and one equal to or greater than 3.5. PC-11 oils with HTHS viscosity <3.5 would offer FE benefits but would be restricted to engines designed to run on lower HTHS viscosity oils. This may exclude many older engines. Engine manufacturers are evaluating their hardware to see if engine durability, especially for ring and liner scuffing is an issue with low HTHS viscosity oils so they can take advantage of the engine lubricant delivering improved FE to meet the new US Environmental Protection Agency (EPA) and National Highway Traffic Safety Administration (NHTSA) FE and GHG requirements. Engine manufacturers may have to redesign their engines to take advantage of the potential fuel savings of low HTHS viscosity oils. PC-11 oils with HTHS viscosity equal to or greater than 3.5 would cover the heritage fleet and new engine requiring higher HTHS viscosity for wear protection. 還有影片： http://www.hddeo.com/video/hths.html 國外還有專門測試的儀器： http://www.cannoninstrument.com/high-temperature%20high-shear%20viscometer%20hths.pdf 為了節能減碳又省油，有些廠商希望藉由降低HTHS來省油，但是前提是引擎設計與材質必須夠好，但並代表HTHS就是無意義的數值，國內機車的廠商又願意花多少研發經費在引擎設計上呢？常常是一個萬年引擎套個新設計外殼，頂多只是小修改。 至於我拿AMO & Mobil1 0w40來比較，是因為這篇是討論機油濃度的高溫保護性，而不是討論同係數等級的機油，請了解標題之後再討論，而且二款我有使用過的經驗與照片，如果有意見的人也請提供使用心得。 所以HTHS不能代表一切，卻也是一個重要的參考數據，再附上一些大家常用的油與HTHS數據提供參考 AMSOIL MCF 10W40 HTHS:4.5 AMSOIL AMO 10W40 HTHS:4.3 Mobil 1 0W-40 HTHS:3.8 MOBIL 1 5W-50 HTHS:4.4 SHELL HELIX ULTRA 5W-40 HTHS:3.68 Castrol edge 10W40 HTHS:2.9 Red Line 0W40 HTHS:4.0 Red Line 5W40 HTHS:4.6 Q8 Moto SBK Racing 10W-50 HTHS:3.5
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