

🛵 Ride Bold, Ride Red: The Synthetic Oil That Means Business
Red Line 42504 20W50 Synthetic Motorcycle Oil is a premium, ester-based lubricant designed specifically for modern Big-Twin engines. Featuring 2200 ppm ZDDP for superior antiwear protection and friction modifiers compatible with wet clutches, it ensures optimal engine performance and longevity under high-temperature and high-stress conditions. Trusted since 1979, this quart-sized oil delivers smooth shifting, quieter operation, and reliable protection for your motorcycle’s heart.






| ASIN | B003TQ3JQ4 |
| Automotive Fit Type | Universal Fit |
| Best Sellers Rank | #59,617 in Automotive ( See Top 100 in Automotive ) #459 in Motor Oils |
| Brand | Red Line |
| Customer Reviews | 4.8 4.8 out of 5 stars (620) |
| Date First Available | January 30, 2010 |
| Exterior | Painted |
| Global Trade Identification Number | 00083522425049 |
| Is Discontinued By Manufacturer | No |
| Item Weight | 1.26 pounds |
| Item model number | RED42504 |
| Manufacturer | Red Line |
| Manufacturer Part Number | 42504 |
| Model | 42504 |
| OEM Part Number | 42504 |
| Product Dimensions | 4.5 x 3.5 x 9 inches |
| SAE J300 Viscosity Grade | 20W-50 |
| Size | Quart |
| UPC | 083522425049 |
| Vehicle Service Type | ATV, Sport Motorcycle |
| Viscosity | 20W-50 |
N**E
Great motorcycle Oil
Great motorcycle oil. It shifts and runs much better - quieter & smoother.
C**S
Fast delivery.
Fast delivery. This is great oil. It stays relatively clean even when running hard in high dust conditions. Knowing that this oil does well in high temp enviroments, give me some peace of mind when stuck in traffic on a hot summer day. I run it is a '23 Lowrider ST.
I**T
Good
Good product
C**A
Not that it was bad oil, just not worth the extra 3 to ...
I've been using this oil in my 2005 Buell XB12 for over nine years. I started out with the Harley branded synthetic oil. Then I learned that Harley just rebranded a blended oil from a big-name manufacturer. Not that it was bad oil, just not worth the extra 3 to 4 dollars over mobile one or Castrol V-twin oil. The thing about red line is it is a pure synthetic. Does it make a difference for a regular street bike, I can't really say. The Bull engine is air cooled and runs really hot, especially here in the south. Getting stuck in summer afternoon traffic on the highway is absolute murder. I also like to run the occasional track day, just for fun. After all these years and at about 50,000 miles The bike still runs like new. I opened up the engine to add some hotter cams... and I was surprised to see almost no wear on any metal surfaces. I can't say the redline does something that other oils don't.... but I can't say that it has done an amazing job in my engine.
M**N
Best oil for big V twins.
I started changing my own oil a few years back and tried Red Line for no other reason than the reviews. I have 2 bikes with 103s and an older 88. This oil is amazing compared to the garbage HD uses. You will literally hear and feel your motor run better and quieter. No more clunking or lagging with the throttle. It seems to run so much cooler and smoother. You will not be unhappy with this oil. As a side note, I also use Red Line Primare oil and gear oil and notice a huge difference with them as well. Red Line for all 3 holes.
R**L
Highly recommend
Works great in my Harley
R**N
Good fluid but no sight to see level inside bottle
Absolutely love this fluid. I give it 4 stars because there is no sight level on the bottle. It’s conpletely black. So when doing my oil change which requires an initial fill of 2.5 quarts I have to guess how much is a half quart on the third bottle. Add a clear stripe like literally every manufacturer does to their bottles so we can see the level remaining in the bottle please!!
Z**P
hog runs a lot cooler with this juice
good stuff, i’ve used them all, this juice keeps the hog running cooler on those hot days. i highly recommend the redline shockproof trans juice as well.
T**N
all I use in my bike, switched over to this and the primary and transmission lube. Rating synthetic oil is subjective to say the least. lol. I run it in my roadking and have for several years. works for me.
D**1
huile pour ma mt 01 , réduit fortement le bruit moteur , huile de très bonne qualité , un peu cher , je la recommande
A**R
Satisfaction
Trustpilot
1 month ago
3 days ago