chery tiggo 8 pro how many seater

The most fuel-efficient engine speed when driving is typically between 2000 and 3000 revolutions per minute (rpm), with specific values requiring adjustment based on the vehicle's displacement, transmission type, and road conditions. Gasoline vehicles achieve optimal fuel efficiency within the 2500 to 3000 rpm range, as this ensures complete combustion and stable power output. Diesel vehicles, however, are recommended to operate between 2000 and 2500 rpm. Economical driving speeds are 60 to 70 km/h in 4th gear and 80 to 90 km/h in 5th gear. Small-displacement vehicles perform best at 60 to 80 km/h, while medium-displacement vehicles are most efficient at 80 to 100 km/h. It is important to avoid excessively low rpm to prevent engine lugging, as well as excessively high rpm to minimize unnecessary fuel consumption. Additionally, maintaining a steady speed, gentle acceleration, judicious use of air conditioning, and regular maintenance (such as oil changes and air filter replacements) can further enhance fuel economy. Some high-end models with optimized transmissions may have an economical rpm range as low as 1700 to 1800 rpm, though 2000 to 3000 rpm remains the general benchmark.

When driving at 70 mph (approximately 112 km/h), fuel consumption increases significantly compared to the optimal fuel-efficient speed. According to measured data, when the speed increases from the economical range (70-90 km/h) to 112 km/h, fuel consumption can rise by 21%-28%, specifically manifested as an increase from approximately 5.5 liters per 100 kilometers to 7-8 liters. This difference primarily stems from the exponential growth of air resistance at high speeds, which necessitates higher engine RPM to maintain power output, resulting in reduced fuel efficiency. Notably, fuel consumption curves vary across different vehicle models. For instance, a 1.6L engine vehicle consumes about 4.0 L/100km at 80 km/h, while consumption doubles to 8-9 liters at 120 km/h. To optimize fuel economy, drivers should maintain steady speeds and properly utilize the highest gear. Additionally, regular maintenance of the fuel system (such as cleaning fuel injectors every 40,000 kilometers) helps sustain engine efficiency.

When the vehicle speed is 20 mph (approximately 32 km/h), it is recommended to use third gear for manual transmission vehicles. Third gear is suitable for the medium speed range of 20 to 40 km/h, as it balances power output and fuel economy, making it ideal for smooth driving on urban roads or for slight acceleration needs. If the vehicle is in the low-speed phase after starting (e.g., 10-20 km/h), it is necessary to downshift to second gear to provide sufficient torque; if road conditions allow continuous acceleration beyond 40 km/h, you can gradually shift up to fourth gear. It should be noted that there are differences in transmission gear ratios among different vehicle models. For example, some sport-tuned vehicles may allow second gear to cover speeds up to 35 km/h, while economy vehicles may recommend shifting up earlier to optimize fuel consumption. Automatic transmission vehicles do not require manual intervention, but this logic can also be referenced when switching to S mode or manual mode. In actual driving, adjustments should be made flexibly based on engine speed (usually maintained at 1500-2500 rpm) and road conditions to avoid engine lugging caused by high gear at low speed or excessive fuel consumption caused by low gear at high speed.

Converting engine speed (RPM) to vehicle speed (mph) requires comprehensive consideration of parameters such as tire diameter, transmission gear ratio, and final drive ratio. Taking 1000 RPM as an example, if the tire diameter is 0.6 meters (with a circumference of approximately 1.885 meters), the transmission gear ratio is 1:1, and the final drive ratio is 4:1, the vehicle speed will be approximately 28.3 mph (45.5 km/h). Actual vehicle speed may fluctuate due to factors such as driveline design, tire wear, or load. For instance, high-performance models may achieve lower vehicle speeds at the same RPM in lower gears, while economy vehicles may reach higher speeds in higher gears. It is recommended to refer to the RPM-speed correlation chart in the vehicle manual or use professional diagnostic tools to obtain accurate data. Such tools typically incorporate tire specifications and gear ratio parameters, helping to prevent errors caused by tire modifications or wear.

Calculating the relationship between vehicle speed and engine RPM requires integrating parameters such as tire circumference, transmission gear ratio, and final drive ratio. The basic formula is: RPM = (Vehicle Speed × Gear Ratio × Final Drive Ratio × 60) ÷ (Tire Circumference × 1000). The tire circumference can be calculated from the tire size specification (e.g., the circumference of a 195/55R15 tire is (195×0.55×2 + 15×25.4)×3.1416/1000 meters). For example, at a vehicle speed of 100 km/h, with a tire circumference of 2 meters and a total drive ratio (4th gear ratio 1.0 × final drive ratio 3.5) of 3.5, the RPM would be approximately (100×3.5×60)÷(2×1000) = 1050 RPM. Actual RPM is further influenced by transmission type: CVT transmissions typically operate around 1000 RPM lower than manual transmissions at the same speed, while 8AT models can achieve up to 40% lower RPM compared to 4AT models during highway cruising. Turbocharged engines, owing to their low-RPM high-torque characteristics, maintain 15%-20% lower RPM than naturally aspirated engines under equivalent speeds. For optimal fuel efficiency and power response, maintain an RPM range of 2000-3500 during normal driving; shift up promptly when exceeding 4500 RPM to prevent engine overloading.