{"product_id":"red-line-mt-85-75w-85-gl-4-manual-transmission-gear-oil-1-gallon-synchro-safe-shift-improvement","title":"Red Line MT-85 75W-85 GL-4 Manual Transmission Gear Oil - 1 Gallon, Synchro-Safe Shift Improvement","description":"\u003cp\u003e\u003cstrong\u003eRed Line 50505 MT-85 is a high-performance 75W-85 GL-4 manual transmission gear oil formulated to protect gears and synchros while improving shift feel across a wide temperature range.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eEngineered for modern and classic manual transmissions that require GL-1, GL-3 or GL-4 fluids, this one-gallon pack delivers robust protection without the corrosive reactive sulfurs present in many GL-5 formulations. It balances friction control and lubricity to help synchronizers operate smoothly, supports quicker shifts even in cold conditions, and is safe for brass and bronze synchros commonly found in performance and OEM gearsets.\u003c\/p\u003e\n\n\u003ch3\u003eHow does this oil improve shifting and drivetrain longevity?\u003c\/h3\u003e\n\u003cp\u003eMT-85 combines controlled friction characteristics with durable film strength so synchros engage smoothly while gears remain protected under load. The result is crisper shifts, reduced wear on synchronizer rings, and longer component life when used in compatible applications.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eBalanced friction for consistent shift feel\u003c\/li\u003e\n  \u003cli\u003eFilm strength that resists shear under high torque\u003c\/li\u003e\n  \u003cli\u003eMinimizes synchro wear for extended service intervals\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eIs this safe for vehicles with brass or bronze synchros?\u003c\/h3\u003e\n\u003cp\u003eYes — MT-85 is formulated as a GL-4 gear oil, meaning it omits the reactive sulfur compounds often found in GL-5 products that can attack yellow metals. That makes it suitable for many transmissions that specify GL-1, GL-3, or GL-4 fluids and for performance-oriented gear sets that use brass or bronze synchros.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eFree from aggressive sulfurs that corrode brass\u003c\/li\u003e\n  \u003cli\u003eRecommended for Nissan, Mitsubishi, Hyundai, Kia applications\u003c\/li\u003e\n  \u003cli\u003eMatches OEM recommendations where GL-4 is specified\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhich cars and use cases is this oil commonly recommended for?\u003c\/h3\u003e\n\u003cp\u003eMT-85 is a popular choice for a range of passenger cars and sports cars where GL-4 compatibility and synchro protection are required. It's frequently chosen for Nissan 350Z and 370Z models, many Maxima\/Altima\/Sentra transmissions, Mitsubishi Evolution, and several Hyundai and Kia manuals, as well as aftermarket Quaife gearboxes.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eSports cars with close-ratio gearboxes (e.g., 350Z\/370Z)\u003c\/li\u003e\n  \u003cli\u003eOEM manual transmissions that call for GL-4 or equivalent\u003c\/li\u003e\n  \u003cli\u003eAftermarket limited-slip and boutique transmissions requiring brass-safe oils\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eHow does Red Line’s MT-85 compare to other manual gear oils?\u003c\/h3\u003e\n\u003cp\u003eCompared with standard GL-5 automotive gear oils, MT-85 prioritizes synchro compatibility and predictable friction rather than the extreme pressure additives that can harm yellow metals. It delivers performance-oriented protection and shift quality while avoiding chemistry that can reduce synchronizer life.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eGL-4 chemistry for brass\/bronze compatibility\u003c\/li\u003e\n  \u003cli\u003eTuned friction profile for smoother, quicker shifts\u003c\/li\u003e\n  \u003cli\u003eDesigned for performance and daily-driven manual gearboxes\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho is this for: Drivers who own manual-transmission vehicles that require GL-1\/GL-3\/GL-4 fluids, owners of Nissan 350Z\/370Z and similar models, tuners installing Quaife or other aftermarket gearboxes, and anyone seeking improved shift feel without risking corrosive effects on brass or bronze synchros. Choose Red Line 50505 MT-85 when you want a durable, performance-minded 75W-85 gear oil in a convenient one-gallon size.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Can I use this oil in a transmission that specifies GL-4?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. Red Line MT-85 is formulated to meet GL-4 requirements and is safe for transmissions specifying GL-4, GL-3, or GL-1.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Is MT-85 safe for brass or bronze synchros?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. MT-85 avoids aggressive sulfurs found in GL-5 oils, protecting brass and bronze synchronizers.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"Red Line","offers":[{"title":"Default Title","offer_id":67585017249977,"sku":"B019XB6FQO","price":238.01,"currency_code":"CAD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0822\/3765\/3177\/files\/red-line-mt-85-front-label.jpg?v=1790463553","url":"https:\/\/redleafauto.ca\/products\/red-line-mt-85-75w-85-gl-4-manual-transmission-gear-oil-1-gallon-synchro-safe-shift-improvement","provider":"Redleaf Auto","version":"1.0","type":"link"}