What is considered high CO2 emissions in cars?
High CO2 emissions from a car are typically defined by tailpipe emissions measured in grams per kilometer (g/km) and how far they are above regulatory targets or typical vehicle ranges. In practice, that means large, heavy, or inefficient models tend to emit more; electrified powertrains (BEVs and many PHEVs) are much lower or zero at the tailpipe. For context, regulatory targets in Europe aim for very low fleet average emissions, while other markets use per-mile measurements and fleet standards.
Regional benchmarks and how "high" is defined
European Union: fleet targets and what qualifies as high
In the EU, the standard reference is CO2 emissions per kilometer for new cars, reported under WLTP testing. The fleet-average target is around 95 g/km for new cars, with penalties applying to manufacturers whose combined fleet exceeds the target. Vehicles emit more than this benchmark when they are large, heavy, or powerfully tuned. For everyday buyers, a car emitting roughly 150 g/km or more is typically considered a high-emission option within many segments, especially outside of electrified models.
United States and other markets
The United States uses CO2 emissions per mile (grams per mile) for regulatory purposes. As of recent years, the average new light-duty vehicle has had CO2 emissions in the area of 340–350 g/mi (about 210 g/km), with hybrids and electrified models significantly lower. There isn’t a single universal “high” threshold like Europe’s 95 g/km; instead, authorities compare fleets to standards and impose penalties when targets aren’t met. For consumers, vehicles emitting around 200 g/km or more often represent higher-emission options relative to the market average.
How CO2 is measured and what the numbers mean
Tailpipe CO2 figures indicate the amount of CO2 emitted per distance traveled under standardized tests. The current standard in many regions is WLTP, which provides more realistic results than the older NEDC. Some advertised numbers may still reference older tests or be adjusted for vehicle options. It's important to note that CO2 figures reflect only tailpipe emissions and do not account for CO2 produced by electricity generation when charging plug-in vehicles; lifecycle emissions depend on the energy mix of the grid.
Typical ranges by vehicle class (a quick guide)
To illustrate what “high” means in practice, here is an approximate snapshot of tailpipe CO2 ranges by vehicle type. Exact numbers vary by model and spec, and BEVs have zero tailpipe CO2 by definition.
- Battery electric vehicles (BEVs): 0 g/km (tailpipe)
- Plug-in hybrids (PHEVs): roughly 20–60 g/km when driven mainly on electricity; 60–100 g/km when the internal combustion engine runs more frequently
- Small petrol cars: about 100–120 g/km
- Compact and mid-size petrol cars: about 120–170 g/km
- Diesel variants: roughly 100–130 g/km depending on size and tuning
- SUVs and crossovers: about 150–230 g/km, with larger or performance-oriented models higher
- High-performance and large luxury cars: often above 200 g/km
These figures reflect typical market vehicles and are influenced by weight, aerodynamics, drivetrain efficiency, and driving style. For buyers seeking lower emissions, aiming toward the lower end of these ranges or toward electrified powertrains generally yields the best results.
What to look for when choosing a car to reduce CO2
If reducing CO2 is a priority, consider these guidance points when shopping for a vehicle.
- Opt for electrified powertrains: BEV or PHEV to substantially lower tailpipe emissions.
- Choose smaller, lighter, and more efficient models; compare official WLTP CO2 figures rather than only fuel economy.
- Check the electric range and charging options for PHEVs and BEVs to maximize electric driving and minimize gasoline use.
- Be aware of regional incentives, taxes, and total cost of ownership tied to low-emission vehicles.
By prioritizing electrification and efficiency, buyers can significantly reduce their vehicle-related CO2 footprint, while policymakers continue to push for lower fleet emissions via standards and incentives.
Summary
High CO2 emissions in cars are defined by tailpipe CO2 output per distance and how far that output exceeds regulatory targets and typical vehicle ranges. In Europe, fleet targets around 95 g/km for new cars drive policy and penalties, while in the United States and other markets, emissions are tracked per mile with fleet standards guiding what counts as high. In everyday terms, conventional gasoline and diesel cars often fall in the 120–180 g/km range, with large SUVs and high-performance models exceeding 200 g/km. BEVs offer zero tailpipe CO2, and PHEVs can be very low when charged and driven predominantly on electricity. For consumers, prioritizing electrified or highly efficient vehicles and checking WLTP-based CO2 figures are the practical ways to reduce high-emission choices.
What is considered high CO2 emissions?
The American Conference of Governmental Industrial Hygienists (ACGIH) recommends an 8- hour TWA Threshold Limit Value (TLV) of 5,000 ppm and a Ceiling exposure limit (not to be exceeded) of 30,000 ppm for a 10-minute period. A value of 40,000 is considered immediately dangerous to life and health (IDLH value).
What is the average CO2 emissions of a car?
about 4.6 metric tons
What is the average annual carbon dioxide (CO2) emissions of a typical passenger vehicle? A typical passenger vehicle emits about 4.6 metric tons of CO2 per year. This assumes the average gasoline vehicle on the road today has a fuel economy of about 22.2 miles per gallon and drives around 11,500 miles per year.
What is the acceptable CO2 level in a car?
Generally, any vehicle that emits below 100 g/km is considered to be a low polluting vehicle which we think is an acceptable level for a modern car. New vehicles have a target of 95 g/km so will be under this already but older models (pre 2021) will not have had to meet this standard.
Can I still drive my car if it says emissions system problem?
Driving with the emission control system warning light on is generally not recommended. While the vehicle may still operate, the warning light indicates that there's an issue with the emission control system that could lead to potential damage to the engine or emission control components.
