# Why Choose Lubri-Loy Automotive Gear Oil 85W-140 (AGO-8W140-640) Over Southwest Oil Co. Gear Oil 85W140 Date: 2026-11-14 Canonical HTML URL: https://lubriloy.com/blog/why-choose-lubri-loy-ago-8w140-640-over-southwest-oil-85w140-gear-oil 85W-140 GEAR OIL, GL-5AGO-8W140-640 # Why Choose Lubri-Loy Automotive Gear Oil 85W-140 (AGO-8W140-640) Over Southwest Oil Co. Gear Oil 85W140 Southwest Oil 85W140 alternative - **Lubri-Loy:** Automotive Gear Oil 85W-140, GL-4 and GL-5 - **Package:** 5 gal pail [Buy AGO-8W140-640 direct](https://lubriloy.com/products/ago-8w140-640)[Request a quote](https://lubriloy.com/support?topic=quote&product=AGO-8W140-640) If you buy Southwest Oil Co. Gear Oil 85W140 in 5 gallon pails, Lubri-Loy's interchange list gives you AGO-8W140-640: Automotive Gear Oil 85W-140 in a 5 gallon pail, available direct from Lubri-Loy. We could not find a public data sheet for Southwest's product, so this page compares only what we can verify: the Lubri-Loy specifications and the interchange pairing. Confirm your application requirements before you switch. ## Quick answer Lubri-Loy's interchange list pairs Southwest Oil Co. Gear Oil 85W140 (5 gal pail) with Lubri-Loy AGO-8W140-640 (5 gal pail), an 85W-140 multipurpose gear oil for severe-service gears. 01Side by side ## Southwest Oil Co. Gear Oil 85W140 vs AGO-8W140-640 | Attribute | Southwest Oil Co. Gear Oil 85W140 | AGO-8W140-640 | | Viscosity grade | 85W-140 | 85W-140 | | API service | See Southwest Oil Co. label or data sheet | GL-4 and GL-5 family; GL-5 recommended for hypoid gears in moderate and severe service | | Specifications | No public data sheet found | Meets MIL-L-2105D, Mack GO-J and Rockwell O-76-D (85W-140), per Lubri-Loy catalog | | Additive system | See Southwest Oil Co. label or data sheet | Sulfur-phosphorus extreme-pressure package for anti-weld, anti-scuff and anti-wear (catalog) | | Package | 5 gal pail | 5 gal pail (AGO-8W140-640); 55 gal drum is AGO-8W140 | Southwest Oil Co. does not publish a data sheet we could locate, so no competitor values are shown. Lubri-Loy values are from the Lubri-Loy catalog. Scroll the table sideways to see every column. 02The case for switching ## Why choose AGO-8W140-640 - 01 ### Buy direct, ship free AGO-8W140-640 is on lubriloy.com with a listed price and free US shipping. Net 30 terms are available by credit application. - 02 ### Severe-service gear protection The catalog describes high quality HVI base stocks with an extreme-pressure additive package for anti-weld, anti-scuff and anti-wear protection. - 03 ### Pail or drum Buy 5 gallon pails now and step up to 55 gallon drums when your usage grows. - 04 ### Since 1949 Lubri-Loy has supplied lubricants since 1949. We source, formulate and package through our network of US blending partners. 03Before the changeover ## Check before you switch Confirm that your axle or transmission maker's required API gear-oil category and any limited-slip requirements match what you buy. If your application calls for a synthetic, Lubri-Loy lists a separate synthetic 85W-140 (AGOS-8W140). Because we could not verify Southwest Oil Co.'s published specifications, compare your current label against the Lubri-Loy catalog sheet before you switch. 04Common questions ## FAQ ### What is the Lubri-Loy equivalent of Southwest Oil Co. Gear Oil 85W140? + Lubri-Loy's interchange list pairs Southwest Oil Co. Gear Oil 85W140 (5 gallon pail) with Lubri-Loy AGO-8W140-640, an 85W-140 automotive gear oil in a 5 gallon pail. ### Is AGO-8W140-640 a GL-5 oil? + Lubri-Loy's catalog lists the AGO line as GL-4 and GL-5 multipurpose gear oils, with GL-5 recommended for hypoid gears in moderate and severe service. ### Is there a synthetic version? + Yes. Lubri-Loy lists a synthetic 85W-140 as AGOS-8W140. ### How do I buy it? + Order on lubriloy.com with free US shipping, or call (877) 582-7456. Premium Lubricants, Without Premium Prices. ## Automotive Gear Oil 85W-140, GL-4 and GL-5 AGO-8W140-640 / 5 gal pail [Buy AGO-8W140-640 direct](https://lubriloy.com/products/ago-8w140-640)[Request a quote](https://lubriloy.com/support?topic=quote&product=AGO-8W140-640) ## Sources Southwest Oil Co. is a trademark of its owner. Product names are trademarks of their respective owners and are used for identification only. Lubri-Loy is not affiliated with or endorsed by them. Competitor figures are from the sources linked above; Lubri-Loy figures are typical values from the Lubri-Loy catalog. Always check the current data sheet before changing products. Premium Lubricants, Without Premium Prices.