Features and Occasionals

More Cars, Less Pollution

By Ashley Miller

Despite more drivers on the road, Tier 3 vehicles and fuel standards will lower emissions in Utah.

If you’re concerned about the Salt Lake Valley’s air quality, you probably know that vehicle emissions make up about half of our air pollution. And with population expected to double along the Wasatch Front by 2050, even more cars will be hitting Utah’s roads and contributing to the problem. But the good news is cars are getting cleaner, and so is the fuel we fill them with.

New cars are way cleaner, especially with new fuel

New federal standards (called Tier 3) for new cars and gas are now in effect, called Tier 3 (Tier 2 standards ran from 2009 through last year). For vehicles, the new standards mean that cars are about 80% cleaner than the Tier 2 standard.

Tier 3 vehicles are arriving in Utah’s dealership lots. This is good news for our air quality. As people replace older, dirtier models with cleaner cars, fewer emissions will enter our airshed.

In a perfect world we would have workable mass transit options and electric vehicles that run on renewable energy. But until combustion engines are truly a thing of the past, we can look forward to having Tier 3 fuels in our gas pumps to help reduce vehicle emissions.

It’s all about the sulfur

The Tier 3 standard for fuel reduces the sulfur content from 30ppm to 10ppm. Burning fuel releases sulfur dioxide into the atmosphere, leading to the for­ma­tion of particulate matter pollution we see all too often during an inversion.

Sulfur also causes problems for catalytic converters. As it builds up, it makes the catalyst function poorly. Less sulfur buildup will increase the life of the catalyst, making the vehicle run cleaner for a longer period of time.

Two of our largest refineries have committed to produce Tier 3 fuels in Utah: Andeavor (formerly Tesoro) and Chevron. A smaller refinery, Silver Eagle, has already begun producing the lower sulfur fuel. Even though the upgrades needed for the local refineries to remove more sulfur from the fuel they produce are quite costly, the cost of complying with Tier 3 fuels for U.S. oil companies will likely not be passed through to customers.

Also, in case you were wondering, older cars can use Tier 3 fuels and the newer cars can use the Tier 2 fuels, all without vehicular harm (and some improvement over a Tier 2 car/gas combo). However, with the perfect combination of a Tier 3 vehicle running on Tier 3 fuel, the emissions reduction will be dramatic.

Check the smog rating

You can identify a cleaner vehicle several ways. The easiest is by the smog rating. The smog rating is for vehicle tailpipe emissions. These pollutants, like the fine particulate matter we see in wintertime and summertime ozone, cause the smog and hazy skies that are so prevalent in this valley. The smog rating is on a scale of one to 10, and vehicles that score a 10 are the cleanest. A vehicle with a smog rating of 8 emits one-fifth of the emissions of a vehicle with a smog rating of 5.

The smog rating is found on the right-hand-side of a new vehicle’s EPA/DOT Fuel Economy and Environment window sticker, or by searching for a used car with the make, model and year on fueleconomy.gov. Of course, Miles Per Gallon (MPG) and fuel economy are also important for our air quality since the less fuel the vehicle burns, the fewer emissions it produces.

An all-electric, or battery-electric vehicle is the only vehicle right now that truly has zero tailpipe emissions. This means EVs have a smog rating of 10. The emissions from electricity generation are an important part of the equation, but even in areas like Utah where our electricity comes from relatively dirty coal-powered plants, the emissions produced by charging an EV are less than the emissions of the average compact conventional vehicle. And as America’s electricity grids become cleaner and fueled by more renewables, charging EVs will become even cleaner. You’ll find that even taking this into consideration, electric vehicles are the cleanest choice for our air quality challenges. Solar panels can make your car even cleaner, provided you are charging during daylight hours.

You may recall hearing about a resolution passed in 2017 during the last legislative session encouraging Utahns to consider a smog rating when purchasing a vehicle. Representative Patrice Arent and Senator Brian Shiozawa, along with 46 co-sponsors from the Utah House of Representatives ran HCR 18. The resolution recognizes how vehicle emissions impact Utah’s air quality, acknowledges the air quality benefits of purchasing a vehicle with a smog rating of eight or higher, and encourages Utahns buying new cars to consider the air and other environmental impacts when purchasing their next vehicle. The resolution passed and lays a great foundation for a statewide educational campaign.

We live in a delicate airshed. We all must do our part to contribute to cleaner air. Consider the smog rating when purchasing a vehicle. It’s just the sort of thing we can do as individuals to improve the air we all breathe.

CATALYST welcomes Ashley Miller, J.D., as our new air quality columnist. Miller is program and policy director for Breathe Utah. She was recently appointed to the state’s new Air Quality Policy Advisory Board and is also a member of the SL County Health Department Environmental Quality Advisory Commission.


This article was originally published on October 30, 2017.