9. Mitsubishi 3-cylinder
The 1.2-liter sewing machine of an engine has extremely slow acceleration, and critics claim that highway passing with this car is both time consuming and dangerous. Buyers can also expect a great deal of racket coming from the motor itself, with one critic at Kelley Blue Book referring to it as, “more noise, vibration and harshness than you’ll get by putting bolts in a blender.”
8. Mopar 2.2-liter
Its marketing campaign may have made it look like a winner, but the Mopar 2.2 quickly became known as a rod-knocker — and that was before Chrysler tossed a complicated turbocharger into the mix. Everything from the Dodge Daytona to minivans were receiving these powertrains in the 1980s, and almost all of them met the same fate in due time.
Often referred to as “the diesel debacle,” General Motors’ decision to put crude combustion technology in an array of Oldsmobiles proved to be a costly mistake. Instead of doing the right thing and utilizing a proven turbo-diesel powertrain or engineering a new one, the Detroit giant opted to “convert” gasoline engines in order to cut development costs. Buyers didn’t see just horrible performance numbers (120 horsepower and 220 pound-feet of torque), they also got one of the most problematic engines in history, which some still blame for ruining America’s interest in diesel cars.
6. Lexus 2.5 V6
It may have offered a plethora of modern technologies and the initials “V” and “6,” but the lackluster motor from the previous generation IS 250 was anything but athletic. Power came from a pipsqueak of a 2.5-liter V6 that was both undersized and overly constricted by power-robbing emissions systems, leaving both critics and drivers underwhelmed.
On a good day the anemic V6 produced 204 horsepower and 185 pound-feet of torque, which is just barely more than what you’ll find in the old Honda Civic Si, which had two fewer cylinders. Back in 2013, Consumer Reports referred to the old Lexus 250 as “neither sporty nor luxurious,” and dinged it heavily for having acceleration that “lacks punch.” Critics were also extremely disappointed with observed overall fuel economy ratings, which compared with bigger V6’s hovered at a 20/23/27 average according to the EPA.
5. Chevy 2.2-liter Ecotec
Don’t worry folks, the new 2.2-liter Ecotec is perfectly fine, it’s the pre-2006 generation that you have to watch out for. The four-cylinder engine was infamous for refusing to provide power or reliability, instead insisting on things like fresh head gaskets and timing chain components.
Offered in everything from the Cavalier to the S-10 pickup, press reviews at the time urged buyers to stay away from attaching these engines due to poor performance. While a lack of power and durability were troublesome, corroding steel freeze plugs after 50,000 miles were one of the first-gen Ecotec’s major weaknesses. Editors at Hot Rod Network despised the problematic powerplant so much that they claim, “It’s no wonder GM used absolutely no engineering or design from this engine when developing the [new] Ecotec.”
4. The First Ford V8
The iconic Ford flathead was the first production V8 engine from The Blue Oval, and remained in production for over 20 years. It was an engine that was designed to move Americans into a new, faster era of transportation. But history could have turned out very differently…
3. Jaguar V12
Hemmings finds that heat tends to be the cause of most V12 Jaguar engine issues. Since ignition and fuel were in close proximity to one another within the piping hot valley of the “V,” both were prone to failure over time. And while this design was purposefully chosen to alleviate space constraints and worked well in the beginning, many gearheads still look at these engines as ticking time bombs.
2. Subaru 2.0 and 2.5-liter (non-turbo)
Both 2.0- and 2.5-liter versions of the naturally aspirated boxer engine from Subaru have been objects of scrutiny in recent years due to excessive oil consumption. Initially waved off as something that “Subaru engines do,” owners were told they need not worry if they added a quart of synthetic every few thousand miles. If the idea of a brand-new engine burning oil right off the lot concerns you, it should. It even led to the government stepping in.
The tipping point came in 2016, when Subaru finally admitted guilt and agreed to reimburse owners for repair costs and extend the length of their warranties. In a public statement, Subaru confessed that a defective piston ring could cause some 2011–2015 vehicles to excessively burn oil, prompting a lawsuit that alleged that Subaru knew about the problem but neglected to tell owners. Dealers had to to replace countless numbers of short blocks, a fact that lands this duo of boxer motors a number two spot on today’s list.
1. Yugo 55
In late 1983, the Yugo 55 came with a 1.1-liter carbureted engine that generated an abysmal 55 horsepower and had one of the worst reliability ratings in history. With a top speed of just 86 miles per hour (if you were daring and going downhill), the Serbian subcompact was the slowest car sold in the United States at the time, and was problematic to say the least.