PRODUCT DETAILS
MFactory Final Drive Gear Set - D15 & D16 (4.50, 4.70, 4.90)
A final drive change is the cheapest real acceleration you can buy for a D-series. You're not making more power, you're multiplying the power you already have through every single gear. On an engine that was never going to make big numbers, that's often the smartest money in the whole build. Available in 4.50, 4.70, and 4.90 to suit how you actually use the car.
What A Final Drive Actually Changes
Worth explaining properly, because it's easy to confuse with a gearset.
Your final drive is the last gear reduction between the transmission and your wheels. Every gear passes through it, which means changing it affects all of them at once. A gearset changes individual gear ratios. A final drive shifts the whole transmission.
Go numerically higher and you get more torque multiplication at the wheels in every gear. The car accelerates harder, pulls out of corners more willingly, and feels considerably more alive off the line.
The trade is speed per gear. You'll be shifting sooner, your rpm at a given road speed goes up, and top speed comes down. On a D-series that's usually a good trade, since you're rarely running out of road and you're frequently wishing the car pulled harder.
Know Your Starting Point
This matters more than people expect, because how much change you get depends entirely on what you're coming from.
A D16Z6 typically runs a 4.250 final drive from the factory. Moving to a 4.70 is a meaningful step, and a 4.90 is aggressive.
A D16Y8 typically runs 3.722, which is considerably taller. From there, even a 4.50 is a big change, and a 4.90 transforms the car entirely.
So a Y8 owner and a Z6 owner buying the same 4.70 are having very different experiences. Check what you're actually starting with before you decide how far to go, because the same part number means different things depending on your transmission.
Which Ratio Should You Pick?
Three options, and the right one depends on what the car is for and where you're starting.
4.50 (MFT-TRS-02D45) is the moderate step from a Z6 and a substantial one from a Y8. Noticeably quicker while keeping highway rpm reasonable. If the car is a daily you also enjoy, this is the safe pick and you won't regret it on a road trip.
4.70 (MFT-TRS-02D47) is the middle ground and probably the most popular. A real change in how the car accelerates, still livable on the street, and well suited to autocross or a weekend car that occasionally sees a highway.
4.90 (MFT-TRS-02D49) is the aggressive option. Excellent for autocross, track use, and tight technical driving where you're living in the low gears. On the highway you'll be spinning noticeably higher rpm, and that gets tiring on a long drive.
Be honest about your commute before picking. Almost everyone wants the shortest ratio until they've driven ninety minutes on the freeway with it.
Pair It With A Limited Slip
Worth thinking about seriously, because this is where a lot of the gain actually gets realized.
More torque multiplication means more torque at the wheels, and on a front-drive car with an open differential, more torque at the wheels means more wheelspin from the unloaded side. A shorter final drive can genuinely make an open-diff car worse out of a corner, because you're feeding more torque into a system with no way to manage it.
The MFactory limited slip differential for the D-series is what fixes that. It sends power to the wheel with grip instead of the one spinning, so the gearing you paid for actually reaches the road.
And practically, both parts require splitting the transmission case. Doing them together means one job instead of two, which on a gearbox that has to come out of the car is a significant saving in time and money.
What Else To Sort While You're In There
Installing a final drive means the case is apart, so use the access.
Your speedometer will read wrong. Changing the final drive changes how fast the output turns relative to your wheels, so your speedo and odometer will be off. Plan on a correction, whether that's a speedo gear, a recalibration, or accounting for it in your gauges.
Inspect bearings and seals. Anything you have to remove to reach the ring gear should go back in fresh if it has real miles on it. Axle seals and bearings cost almost nothing next to the labor of getting to them.
Look at your synchros. On a Civic that's now thirty years old, this is the ideal moment to deal with grinding rather than pulling the transmission again in a year.
Mention it to your tuner. Gearing changes how load builds in each gear, so if the car is tuned it's worth a conversation.
Fitment
1992-2000 Honda Civic
1993-1997 Honda Del Sol
Fits D15 and D16 transmissions with S20 and S40 cases. Select your ratio at checkout.
Who Should Run One
This is for the D-series owner who's realized their engine is never going to make big power and has decided to make the power it has count for more. Autocross, canyon roads, or a street car you want feeling urgent rather than adequate. It transforms how the car accelerates without touching the engine, and on a chassis this light the difference is immediate. Check what you're starting from, pick your ratio honestly, sort your speedo, and go enjoy a car that finally pulls.
Fits: 1992-2000 Honda Civic and 1993-1997 Honda Del Sol, D15 and D16 transmissions with S20 or S40 cases. Part numbers: MFT-TRS-02D45 (4.50), MFT-TRS-02D47 (4.70), MFT-TRS-02D49 (4.90). Note: speedometer correction required after installation. Pairs with the MFactory D-series LSD.
1992-1995 Honda Civic CX/DX/EX/LX/VX/Si
1996-2000 Honda Civic CX/DX/EX/LX
1993-1997 Honda Del Sol S/Si