NHTSA lists 3 safety recalls and 51 owner complaints for the 2000 Mitsubishi Diamante. Most complaints involve visibility (27) and engine and engine cooling (7). The EPA rates it 18 mpg combined.
CERTAIN PASSENGER VEHICLES FAIL TO CONFORM TO THE REQUIREMENTS OF FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 208, 'OCCUPANT CRASH PROTECTION.' THE BILINGUAL ENGLISH/SPANISH REMOVABLE AIR BAG WARNING LABELS AFFIXED TO THE DASH AND TO THE SUNVISOR DO NOT MEET THE SIZE REQUIREMENTS OF THE STANDARD.
CERTAIN SPORT UTILITY AND PASSENGER VEHICLES FAIL TO COMPLY WITH FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 225, "CHILD RESTRAINT ANCHORAGE SYSTEMS." THE OWNER'S MANUAL DOES NOT CONTAIN A STEP-BY-STEP DESCRIPTION FOR HEADREST ADJUSTMENT WHEN INSTALLING A CHILD RESTRAINT SYSTEM (CRS) TETHER STRAP.
VEHICLE DESCRIPTION: PASSENGER VEHICLES. THE HEAD OF THE SCREW THAT HOLDS THE RETAINING CLIP FOR THE PARKING BRAKE SHOE CAN BECOME BRITTLE AND BREAK OFF.
Complaints are unverified owner reports to NHTSA and are not normalized for sales volume. One complaint can cite several components.
“MY WIFE AND I NOTICED ANTIFREEZE ODOR COMING IN THROUGH VENTS. WHEN OUR WINDOWS WOULD FOG, OUR DEFROSTER WOULDN'T WORK. THEN OUR PASSENGER SIDE FLOOR WAS SOAKED WITH ANTIFREEZE. WE TOOK THE CAR TO THE DEALER, OUR HEATER CORE WAS LEAKING. COST WAS $1300 TO REPAIR. MITSUBISHI SHOULD BE HELD RESPONSIBLE!! TOO MANY COMPLAINTS. *TR”
“THE FUMES OF ANTIFREEZE FOGGED UP THE WINDOWS SEVERELY, REDUCING VISIBILITY OF THE DRIVER. IT WAS RAINING ONE NIGHT AND MY WINDOWS ALL OF A SUDDEN GOT FOGGY. I TURNED ON THE DEFROSTER, WHICH MADE MY WINDOWS EVEN FOGGIER. THE POOR VISIBILITY CAUSED ME TO RUN OFF THE ROAD INTO THE GRASSY MEDIAN. I WAS OUT OF TOWN WHEN THIS OCCURRED. IN DOING RESEARCH ON THIS PROBLEM I FOUND THAT IT WAS COMMON ALL DIAMANTES (92 -2001). IN MANY CASES, THE DRIVER IS NOT AWARE THAT THIS IS A SEVERE PROBLEM. THE ANTIFREEZE WILL STARTED LEAKING ON THE PASSENGER?S SIDE AREA. CAUSING MORE STRONG SMELL OF TOXIC ANTIFREEZE. I BELIEVE THIS TO BE A SAFETY ISSUE. *AK”
“2000 MITSUBISHI DIAMANTE. CONSUMER STATES VEHICLE SURGED FORWARD. *TGW THE CONSUMER STATED WHEN LEAVING A PARKING LOT AND ATTEMPTING TO PULL INTO TRAFFIC, THE VEHICLE BARELY MOVED AT 5 MPH, EVEN THOUGH HE WAS PRESSING ON THE ACCELERATOR AND THE RPM WAS NOT MOVING. AFTER GOING ABOUT 1/4 OF A MILE, ALL OF A SUDDEN THE VEHICLE JUMPED INTO GEAR AND THE VEHICLE LURCHED FORWARD. THE NEXT DAY, A REPRESENTATIVE FROM MITSUBISHI WENT TO THE CONSUMER'S WORKPLACE AND EXAMINED THE VEHICLE. THE REPRESENTATIVE STATED THE THROTTLE CABLE NEEDED TO BE ADJUSTED AND SUGGESTED THE CONSUMER TAKE THE VEHICLE TO THE DEALER. THE CONSUMER STATED THE DEALER NEVER RECEIVED ANY INFORMATION TO ORDER A NEW CABLE AND THE HIS VEHICLE STILL HAS NOT BEEN FIXED. *JB”
Towing, payload and dimensions aren’t in the EPA or NHTSA data, so we don’t list them.
| Version | City | Hwy | Comb. | Fuel / yr | CO₂ g/mi |
|---|---|---|---|---|---|
| Diamante Auto 4-spd, 6 cyl, 3.5 L · Front-Wheel Drive | 16 | 23 | 18 | $4,200 | 494 |
| Item | Miles | Time | Note |
|---|---|---|---|
| Engine oil & filter | 5,000–10,000 mi | 6–12 months | Follow the oil-life monitor if fitted |
| Tire rotation | 5,000–7,500 mi | Every oil change | Check pressure monthly |
| Engine air filter | 15,000–30,000 mi | 1–2 years | Sooner in dusty areas |
| Cabin air filter | 15,000–25,000 mi | 1–2 years | |
| Brake fluid | — | 2–3 years | Absorbs moisture over time |
| Coolant | 60,000–100,000 mi | 5–10 years | Long-life coolants last longer |
| Spark plugs | 60,000–100,000 mi | — | Iridium/platinum plugs at the long end |
| 12V battery | — | 3–5 years | Heat shortens battery life |
3 safety recalls as of Nov 12, 2026, according to NHTSA. Recall repairs are free at a dealer. Check your VIN to see whether your car is included and whether the repair was done.
Owners filed 51 complaints with NHTSA. The most-cited components are visibility (27), engine and engine cooling (7), vehicle speed control (3). Complaints are unverified owner reports and aren't adjusted for how many cars were sold.
The EPA rates the 2000 Mitsubishi Diamante at 18 mpg combined, depending on engine and drivetrain (1 version rated).