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RC Diff Oil Chart: Front, Center & Rear Weights by Car

Differential oil weights for 50 popular off-road RC cars, taken from real race setups and the manufacturers' own team sheets - 1/8, 1/10 4WD and 1/10 2WD, plus what thicker or thinner fluid does at each diff.

Wondering what diff fluid you should run in your off-road RC car? Check out the tables below to find a starting point - most popular current race cars are listed. The bold number is a viscosity (weight) that should work in most conditions. The range shown below each number shows the range that most racers use for that car. People normally use thicker fluid on smooth, high grip tracks (especially carpet), and lighter fluid on low-grip dirt tracks. All figures are in cSt.

1/8 Off-Road Diff Fluid Weights - Buggy & Truggy

Car	Front	Center	Rear
Team Associated RC8 B4.1e	9,000 7,000–10,000	8,000 5,000–10,000	6,000 4,000–7,000
Team Associated RC8 T4e	15,000 8,000–15,000	10,000 8,000–15,000	7,000 6,000–10,000
Team Associated RC8 B4.1	8,000 7,000–15,000	10,000 7,000–12,500	7,000 4,000–10,000
Team Associated RC8 B4e	8,000 4,000–12,500	6,000 5,000–20,000	6,000 4,000–8,000
Team Associated RC8 B3.2	7,000 6,000–10,000	7,000 5,000–10,000	6,000 3,000–7,000
Team Associated RC8 T3.2e	10,000 10,000–20,000	7,000	5,000
Team Associated RC8 B4	7,000 7,000–15,000	7,000 4,000–10,000	6,000 5,000–7,000
Team Associated RC8 B3.2e	10,000 5,000–15,000	7,000 5,000–10,000	5,000 4,000–7,000
TLR 8IGHT-XE 2.0	7,000 5,000–7,000	5,000 4,000–7,000	4,000 4,000–5,000
TLR 8IGHT-X Elite	7,000 5,000–10,000	7,000 7,000–20,000	4,000 3,000–10,000
TLR 8IGHT-XE Elite	7,000 7,000–9,000	7,000	4,000 4,000–5,000
TLR 8IGHT-X 2.0	12,500 7,000–15,000	10,000 5,000–12,500	7,000 4,000–10,000
TLR 8IGHT-XE	7,000	7,000 5,000–15,000	3,000 3,000–4,000
Tekno EB48 2.0	9,000 7,000–12,500	7,000 5,000–10,000	5,000 4,000–7,000
Tekno EB48 2.2	10,000 7,000–10,000	7,000 5,000–10,000	5,000 4,000–7,000
Tekno NB48 2.2	8,000 7,000–15,000	8,000 5,000–20,000	5,000 4,000–8,000
Tekno EB48 2.1	8,000 5,000–30,000	7,000 6,000–7,000	6,000 4,000–20,000
HB D819RS	7,000 5,000–7,000	5,000 5,000–7,000	3,000 2,000–4,000
HB E819RS	7,000 5,000–10,000	5,000 5,000–10,000	2,000 2,000–5,000
Mugen Seiki MBX8 Worlds Edition	7,000 5,000–10,000	7,000 5,000–8,000	5,000 2,000–5,000
Mugen Seiki MBX8	7,000 5,000–9,000	4,000 3,000–6,000	3,000 2,000–4,000
Mugen Seiki MBX8R	8,000 7,000–10,000	8,000 7,000–10,000	5,000 4,000–7,000
Mugen Seiki MBX8TR ECO	10,000 10,000–12,500	10,000 8,000–20,000	7,000
Kyosho Inferno MP10	7,000 5,000–15,000	7,000 5,000–20,000	5,000 3,000–7,000
XRAY XB8E '20-'22	7,000 6,000–20,000	7,000 7,000–15,000	3,000 2,000–3,000
ARRMA Typhon TLR-Tuned	7,000	9,000 3,000–10,000	5,000 4,000–5,000
Serpent SRX8 PRO	7,000 5,000–12,500	8,000 7,000–12,500	3,000 3,000–7,000
Serpent SRX8E PRO	7,000 5,000–10,000	7,000 5,000–10,000	3,000 3,000–4,000
Serpent SRX8E	7,000 7,000–12,500	7,000 7,000–10,000	3,000 3,000–5,000
Serpent SRX8T	7,000 7,000–10,000	7,000 5,000–12,500	5,000 3,000–7,000
SWORKz S35-4	7,000 7,000–10,000	7,000 7,000–10,000	4,000 3,000–6,000

All values in cSt.

Truggy vs Buggy Baselines

If your truggy isn't in the 1/8 table above, start from the buggy on the same platform and go thicker/heavier. Truggies of course, have bigger, heavier tires and load the drivetrain harder, so thicker fluids are necessary. So, if you know what fluid you use in a buggy, you can scale that number up, roughly following these ratios:

Diff	Typical increase over your buggy oil	Example
Front	×1.5 (buggy weight x 1.5 = truggy weight)	8,000 → 12,000
Center	×1.5	8,000 → 12,000
Rear	×1.25	4,000 → 5,000

This is a starting direction, not an exact formula — some platforms move more than others.

1/10 Off-Road Diff Fluid Weights - 4WD

A dash in the center column means the car has no fluid-filled center diff, so there is nothing to set there.

Car	Front	Center	Rear
Team Associated RC10 B74.1	10,000 7,000–30,000	200,000 40,000–500,000	10,000 7,000–15,000
Team Associated RC10 B74.2/D	15,000 10,000–30,000	200,000 200,000–1,000,000	15,000 8,000–60,000
Team Associated RC10 B74.1D	8,000 7,000–10,000	200,000 100,000–500,000	7,000 3,000–15,000
Team Associated RC10 B74	10,000 10,000–15,000	200,000	7,000 7,000–10,000
TLR 22X-4	7,000 7,000–10,000	500,000 200,000–500,000	5,000 4,000–7,000
TLR 22X-4 2.0	10,000 5,000–60,000	500,000 100,000–500,000	7,000 5,000–7,000
Tekno ET410.2	7,000 7,000–30,000	100,000 30,000–200,000	7,000 7,000–15,000
Tekno EB410.2	12,500 7,000–20,000	40,000 15,000–80,000	10,000 5,000–12,500
Schumacher CAT L1R	12,500 10,000–15,000	—	12,500 7,000–15,000
Schumacher CAT PB	12,500 12,500–40,000	—	12,500 12,500–30,000
Serpent SRX4 Gen3	15,000 10,000–30,000	—	10,000 7,000–15,000

All values in cSt.

Center diff or slipper?

Some 1/10 4WD cars use a center diff, some use a slipper clutch, and some let you run either. If you're not sure which to run, check out some of these guides:

Should You Use a Slipper or Differential in the Middle of your 4WD RC Car?
How to Set a Slipper Clutch
Slipper clutch and differential fluid in the settings guide

Choosing diff oils for the front, center and rear

The exact numbers change from car to car, but how front, center and rear compare to each other stays much the same within a class. Use it to sanity-check a setup, or to get close on a car that isn't in the tables.

Class	Front	Center	Rear
1/8 off-road	1.8×	1.7×	1×
1/10 4WD	1×	25×	1×

In 1/8 the front and center are usually similar, and they both run roughly three-quarters thicker (rear weight x 1.75) than the rear. In 1/10 4WD the front and rear usually match, and the center is usually much heavier.

1/10 Off-Road Diff Fluid Weights - 2WD

A 2WD buggy has one differential, in the transmission, and it is either a gear or ball diff.

A gear diff is a sealed case filled with silicone oil. You choose the oil's viscosity (weight) to tune the differential's behavior. Heavier oils give more resistance to the differential action and are typically used for smooth, high-grip tracks.
A ball diff has grease for lubrication, and it's behavior is set by how tight you set the diff screw. Setup sheets usually note the diff setting as “med tight” or a number of turns back from fully tight.

Not sure which one is in your car? Look for a slotted screw through the outdrive - that is used for adjusting the ball diff, and a gear diff does not have one.

Which diff to run

Most cars are sold in two versions. Team Associated do a carpet-oriented B7 and a dirt-oriented B7D; XRAY do the same with the XB2C and XB2D. Do not go by the badge, though — plenty of racers swap the diff once their track's grip comes up.

The more grip, the more likely you want a gear diff. Ball diffs are the norm on dirt and medium-grip clay. Gear diffs take over on carpet, and on astroturf and smooth high-grip clay.

Gear diff oil by car, 2WD

Car	Typical fluid	Range racers run
Team Associated B6 series	7,000	6,000–10,000
Team Associated B7 & B7.1	100,000	60,000–150,000
Team Associated T6 (truck)	10,000	7,000–15,000
TLR 22 5.0 & 22X	12,500	5,000–30,000
XRAY XB2	7,000 low grip 15,000 medium 80,000 high grip	3,000–200,000
Schumacher Cougar LD2	10,000	3,000–50,000
Schumacher Cougar LD3	60,000	5,000–200,000
Yokomo YZ-2	7,000	3,000–12,500

All values in cSt.

Grip moves this number more than anything else. The XRAY XB2 shows it best — the same buggy runs 7,000 on a low-grip track and 80,000 on a high-bite one.

What fluid viscosity (weight) does

Once you have a baseline, this is which way to move it. These effects hold on any car.

Diff	Thicker	Thinner
Front	More steering off-power and into the corner; can push mid-corner and make the car harder to turn on power	Frees the front, more on-power steering, less entry bite
Center	More forward drive on power, more stable on rough ground; harder to rotate, more understeer	Easier to rotate, more responsive; can spin up and lose drive on low grip
Rear	More rear traction and stability on power, more forward bite	More rotation and steering on power; less side bite

Grip is the main lever: thicker as it comes up, thinner as the track gets loose, dusty or bumpy. Big jumps are the exception — a thicker center keeps the car settled in the air and on landing, rough track or not.

Going deeper: Off-road Differential Tuning with Dakotah Phend, How to Choose Diff Fluid for your Off-road RC Car, Choosing 4WD Diff Oil for Off-road, and What is “diffing out”?

Where to buy diff fluid

Each link opens that brand's diff oil at AMain, where you pick the weight you need.

Brand	Bottle
Team Associated	2 oz	View weights at AMain →
TLR	30 ml	View weights at AMain →
Mugen Seiki	50 ml	View weights at AMain →
Kyosho	40 cc	View weights at AMain →
JConcepts	20 ml	View weights at AMain →
Hudy	50 ml	View weights at AMain →
Core-RC	50 ml	View weights at AMain →
1UP Racing	—	View weights at AMain →
Flash Point	75 ml	View weights at AMain →
J&T Bearing Co.	2 oz	View weights at AMain →
Pit Bull	2 oz	View weights at AMain →
Traxxas	—	View weights at AMain →

You do not have to match the brand of your car. Every brand labels diff oil in cSt, but there is usually some variation in actual viscosity between fluids from different brands even if they are labeled as the same weight.

Setting up shocks too? See the RC shock oil viscosity chart — shock oil is labeled differently by brand and does need converting.