Tech Dive: How the Chevy Cruze Diesel Stays Clean

Bozi Tatarevic
by Bozi Tatarevic
tech dive how the chevy cruze diesel stays clean

Volkswagen may not be the only one that was cheating on their emissions testing. Reports coming out of the European Federation for Transport and Environment are shining light on other manufacturers which could be putting out dodgy emissions figures. I found the Vauxhall Zafira Tourer on one such report and decided to take a look at the Chevy Cruze Diesel due to related engine technology. I was surprised by what I found.

The Zafira Tourer can be equipped with a choice of two diesel engines. The lower trim features a 1.6-liter mill that produces 134 horsepower. The higher trim features a 2.0-liter engine that produces 163 horsepower. The 1.6-liter engine was mentioned in the T&E report as producing 9.5 times more emissions in their real world test than the law allows.

While General Motors may have some explaining to do for the 1.6-liter diesel in Europe, the 2.0-liter may actually be as clean as it promises.

The Cruze Diesel 2.0-liter engine is based on the one of the same size used in Europe, but many changes have been made including a new intake manifold, throttle body system and ceramic glow plugs. The fuel system was also modified to run at 1,600 PSI instead of the 2,000 PSI they see in Europe. Changes in the emissions programming were also made in order to meet U.S. emissions requirements. Both engines employ a diesel particulate filter (DPF) along with a urea injection system.

GM may have paved the way for a Volkswagen fix since they were able to lower the NOx output from their engine by making a few hardware changes and adjusting the emissions programming to reduce fueling. These changes are apparent when you look at the specs for the vehicles.

The European engine produces 163 hp and 260 lb.-ft. while the US engine produces 151 hp and 250 lb.-ft.

The fuel economy is also noticeably better for the European version with the heavier Zafira Tourer enjoying a 40 mpg combined rating while the Cruze Diesel is rated at 33 mpg combined by the EPA. All of these changes fall in line with a reduction in fuel injection timing. Reducing the timing causes a decrease in power and fuel economy, but also reduces the NOx output.

One other hint to the changes lies in the CO2 output ratings which put the Zafira Tourer at 220 grams per mile while the Cruze is at 307 grams per mile. This goes in line with a lower NOx output rating for the Cruze as due to the inverse relationship of CO2 and NOx output.

The dirty piece of reducing the injection timing is that more soot is created, which is why many are against such a fix for the Volkswagen diesels. This side effect is apparent in the Cruze as many have complained about soot buildup and the ability of the diesel regen cycle to clean it. The regen cycle in the Cruze burns additional diesel to heat up the particulate filter and clear out the soot, but dealers are running manual regens or increasing the regen cycle to help combat these issues due to the heavy soot build up on some vehicles. While the longer regen cycles will help to combat soot, they will also reduce the fuel economy as more diesel is dumped in order to heat up the filter.

The last piece of the puzzle lies with the aftermarket tuners and how much power they’ve been able to add with just a change in programming. The tuners were able to add 39 horsepower and 50 ft-lbs of torque to the Cruze without making any hardware changes, which likely equates to an advance in the fuel injection timing along with a change in the transmission torque management. The tuner further advertises that soot and DEF fluid usage are reduced while fuel economy is improved, which falls in line with a reduction of CO2 and an increase in NOx. The tuners have basically created a tune for the Cruze to turn into a calibration similar to what Volkswagen TDIs and the Euro-market Zafira Tourer are currently running.

[Image Credits: General Motors]

Join the conversation
2 of 132 comments
  • Jeff S Corey--We know but we still want to give our support to you and let TTAC know that your articles are excellent and better than what the typical articles are.
  • Jeff S A sport utility vehicle or SUV is a car classification that combines elements of road-going passenger cars with features from off-road vehicles, such as raised ground clearance and four-wheel drive.There is no commonly agreed-upon definition of an SUV and usage of the term varies between countries. Thus, it is "a loose term that traditionally covers a broad range of vehicles with four-wheel drive." Some definitions claim that an SUV must be built on a light truck chassis; however, broader definitions consider any vehicle with off-road design features to be an SUV. A [url=]crossover SUV[/url] is often defined as an SUV built with a unibody construction (as with passenger cars), however, the designations are increasingly blurred because of the capabilities of the vehicles, the labelling by marketers, and electrification of new models.The predecessors to SUVs date back to military and low-volume models from the late 1930s, and the four-wheel drive station wagons and carryalls that began to be introduced in 1949. The 1984 [url=]Jeep Cherokee (XJ)[/url] is considered to be the first SUV in the modern style. Some SUVs produced today use unibody construction; however, in the past, more SUVs used body-on-frame construction. During the late 1990s and early 2000s, the popularity of SUVs greatly increased, often at the expense of the popularity of large [url=]sedans[/url] and station wagons.More recently, smaller SUVs, mid-size, and crossovers have become increasingly popular. SUVs are currently the world's largest automotive segment and accounted for 45.9% of the world's passenger car market in 2021. SUVs have been criticized for a variety of environmental and safety-related reasons. They generally have poorer fuel efficiency and require more resources to manufacture than smaller vehicles, contributing more to climate change and environmental degradation. Between 2010 and 2018 SUVs were the second largest contributor to the global increase in carbon emissions worldwide. Their higher center of gravity increases their risk of rollovers. Their larger mass increases their stopping distance, reduces visibility, and increases damage to other road users in collisions. Their higher front-end profile makes them at least twice as likely to kill pedestrians they hit. Additionally, the psychological sense of security they provide influences drivers to drive less cautiously. the above definition of SUV any vehicle that is not a pickup truck if it is enclosed, doesn't have a trunk, and is jacked up with bigger tires. If the green activists adhere to this definition of what an SUV is there will be millions of vehicles with flat tires which include HRVs, Rav4s, CRVs, Ford Escapes, Buick Encores, and many of compact and subcompact vehicles. The green movement is going to have to recruit millions of new followers and will be busy flattening millions of tires in the US and across the globe. Might be easier to protest.
  • Sckid213 I actually do agree that most Nissans are ultimately junk. (I also think many BMWs are also). I was talking challenging the 3 in terms of driving dynamics. Agree all were failures in sales.
  • THX1136 More accurately said, we are seeing exponential growth in the manufacturing capabilities in this market. Unless, of course, all those vehicles are sold with customers waiting until more a produced so they can buy. Indeed, there are certainly more EVs being purchased now than back in 2016. Is demand outstripping manufacturing? Maybe or maybe not. I sincerely don't know which is why I ask.
  • ToolGuy The page here (linked in the writeup) is ridiculously stupid, seriously stupid, e.g., A) Not sure that particular Volvo is killing the planet as quickly as some other vehicles we might choose. B) A Juke is "huge"??? C) The last picture shows a RAV4 Hybrid?