Key facts & context

• The KG11 platform (for example in Japanese Domestic Market "Bluebird Sylphy" / "Sylphy" models) used the MR20DE engine (2.0 litre, 4-cyl) in certain years.  
• For this engine/transmission combination (2.0L MR20DE + 2WD) the most common transmission is a continuously variable transmission (CVT) designated by RE0F10A (sometimes "Xtronic CVT" in Nissan parlance) when fitted in these models.  
• The listing for used gearbox parts also identifies "MR20 … 2 WD" for the KG11 Sylphy.  

Gearbox / Transmission Description

Transmission type

• The transmission is a CVT unit (RE0F10A) rather than a traditional fixed-gear automatic or manual. This means rather than a set number of gears, it uses a variable ratio belt or chain system inside a pulley assembly to continuously vary the gear ratio.  
• Drive layout: front-engine, front-wheel drive (2WD) for the standard Sylphy KG11 in this engine/transmission configuration.

Key components & features

• Pulley and belt/chain system: The CVT uses a pair of variable-diameter pulleys connected by a high-strength belt or chain that alters its effective diameter to vary gear ratio smoothly. The listing for the gearbox mentions "Chain-driven belt system" and "Adaptive shift control".  
• Transmission Control Unit (TCU): The CVT will be controlled by an electronic unit handling shift logic, belt/pulley ratio adjustment, torque converter lock-up (if present), etc.
• Cooling & fluid: CVTs generate heat, so proper cooling and correct CVT fluid (specific to the unit) are important.
• Gearbox housing & mounting: For the KG11 / MR20DE combination, the gearbox is bolted to the MR20DE engine, and the complete assembly sits in a 2WD layout.

Identification

• A listing for the transmission-assembly for a 2006 DBA-KG11 model shows "Mission Type: RE0F10A" and "Engine Model: MR20".  
• When sourcing used gearbox units or replacements for KG11 with MR20, sellers specify "MR20 transmission – Nissan Serena C25 / Lafesta B30 / Bluebird Sylphy KG11 2004-2013".  

Common Notes & Known Issues

• Because CVTs use a belt/chain and pulleys rather than fixed gears, they require correct fluid and maintenance to avoid premature wear or overheating.
• One forum/expert note for a Sylphy G11 (similar platform) with MR20 indicates that whining noises and burning smells under acceleration can be transmission-related—particularly CVT overheats or wear.  
• When sourcing second-hand units, confirm the correct compatibility (engine code MR20DE, 2WD layout, KG11 chassis) and check condition of the unit, fluid, cooler, etc. Many used listings specify "Used Japan Original … CVT Gear Box Nissan MR20 Fit For Nissan Sylphy KG11 2008-2011 2.0" and include a short warranty.  

Suitability & Application Tips

• If you’re restoring, replacing or servicing the gearbox on a KG11 MR20 2.0 2WD:
  
• Ensure the exact transmission model is RE0F10A (or the correct Nissan CVT model for your region) to match engine and vehicle mounting.
• Check for correct CVT fluid type as specified for the vehicle, and consider replacing fluid and filter (if applicable) when doing gearbox work.
• Inspect the cooler and lines for the CVT, especially in hotter climates (like Malaysia), since overheating is a risk.
• Since the unit is front-wheel drive, ensure alignment and mounting of driveshafts etc are correct to avoid extra load on the gearbox.
• Verify that the "2WD" layout is correct (not AWD) so the gear ratios and casing match your chassis.
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If you like, I can try to locate the exact ratio specifications, service manual excerpts (fluid type, capacity, mounting bolts, cooler layout) for the KG11 MR20 + RE0F10A combo. Would you like me to dig those up?