Royal Purple Manual Transmission Fluid vs Red Line (50204) SAE 75W80 API GL-4 Manual Transmission and Transaxle Lubricant – Car Gear Oil – 1 Quart Bottle

Both options make for good, if unremarkable, Transmission Fluids at the $25 budget range. While they should serve reasonably well, you might want to look into some other options at that price point.

If you're still interested in learning more about the Royal Purple Manual Transmission Fluid and Red Line (50204) SAE 75W80 API GL-4 Manual Transmission and Transaxle Lubricant – Car Gear Oil – 1 Quart Bottle, however, we wrote-up what we know about them:

No sources that do their own in-depth testing have considered the Royal Purple Manual Transmission Fluid to be a good enough purchase for it to earn a sport in their Transmission Fluid roundups, which is typically a bad sign.

As for the Red Line (50204) SAE 75W80 API GL-4 Manual Transmission and Transaxle Lubricant – Car Gear Oil – 1 Quart Bottle - it wasn't considered to be a good enough purchase to earn a spot in any roundups conducted by sources that perform objective hands-on testing, which typically indicates that a product isn't worth its asking price.

As a last step, we wanted to do a head-to-head Royal Purple Manual Transmission Fluid vs. Red Line (50204) SAE 75W80 API GL-4 Manual Transmission and Transaxle Lubricant – Car Gear Oil – 1 Quart Bottle comparison of their review performance but, unfortunately, weren't able to find any review ratings on either product.