10 Used Sedans That Deliver Serious Performance With Mild Tuning

We all know new car prices are higher than ever, and they don’t appear to be cooling off anytime soon. That’s why the used market shouldn’t be overlooked, because some models, even ones that are a generation or two old, can still serve up plenty of fun behind the wheel. When shopping, avoid flagship performance models such as the Mercedes-AMG E63 or the BMW M5 because they are harder and more expensive to maintain. Instead, we’ve put together a list of true sleeper sedans that, with a simple tune, can turn from a humble ride into a legitimate performance monster.

The vehicles are arranged in alphabetical order by manufacturer. Pricing information was accurate at the time of writing and is subject to change.

2007 Acura TL Type S

The Bulletproof Sports Sedan

Acura’s sports sedans are often overlooked by performance diehards, typically because they tend to prioritize comfort and performance equally. This setup makes them somewhat softer than their hard-edged American and German rivals, which usually emphasize raw driving dynamics. But that doesn’t mean Acura can’t build a capable sports sedan. The third-generation TL Type S is a smart buy for anyone seeking an agile sedan with respectable power, and even the option of a manual transmission.

The third-generation TL arrived in the US for the 2004 model year, but the one to get is the facelifted 2007 TL. The Type S variant featured a bigger V6, an engine that’s conservatively tuned in stock form. A simple ECU upgrade paired with intake and exhaust revisions can liberate extra horsepower. At the same time, buyers may also want to add suspension mods to help the front-wheel-drive layout put down the power more effectively. Thanks to the TL’s durability, many used examples carry extremely high mileage, but for those who can stretch the budget, the modern TLX Type S is also worth a look.

2014 BMW 535d

Perfect For Eating Up Highway Miles

Diesel engines have long been pegged as torquey but unrefined workhorses by a US audience. In Europe, they’ve powered sporty, efficient sedans and wagons that can quietly embarrass flashier machines. BMW brought that concept stateside with the 2014 535d, the first diesel-powered 5 Series sold here. Its twin-turbo 3.0-liter inline-6 thrives on simple modifications, with a basic ECU tune unlocking impressive low- and mid-range torque. Even for some of BMW’s diesel models, engine mapping was often the only powertrain differentiator between trim levels.

Sadly, the diesel-powered 5 Series’ run in the US was cut short by the Dieselgate scandal, and BMW phased it out shortly after a 2018 redesign. Today, it stands as an underrated, unassuming, and affordable sleeper on the used market. A caveat is that maintenance and repairs can be expensive, and diesel is also not guaranteed at every gas station.

2014 Cadillac CTS Vsport

A True Sports Sedan That Time Forgot

Cadillac, in recent decades, has built some of the best sports sedans on the market, and the CTS Vsport, based on the third-generation CTS, is right up there. However, since it was never considered a full-blown V model (today replaced by the Blackwing), it’s been overlooked by collectors. It has thus suffered the typical steep depreciation of most luxury sedans.

But this was no mere luxury sedan masquerading as a sports sedan. It came from the factory with a twin-turbo V6 producing 420 horsepower, coupled with 18-inch wheels wrapped in Pirelli tires, Brembo brakes, magnetic dampers, a limited-slip differential, and a heavy-duty track cooling package. The stock power is likely more than enough for most buyers. Other options to improve performance include installing modern tires, such as Michelin’s Pilot Sport 4S, which can vastly improve grip levels compared to the original P Zero Nero all-season tires.

2017 Genesis G80

Honed By A Former BMW M Engineer

Hyundai hit a home run with the first-generation Genesis, but it truly proved it could deliver a sports sedan on par with established luxury brands with the launch of the successor. An ex-BMW M engineering chief even worked on fine-tuning the car’s chassis. The second-generation Genesis arrived for the 2015 model year and was rebranded as the G80 in 2017, when Hyundai introduced Genesis as a standalone luxury brand.

Today, the G80 represents a real bargain for luxury sedan buyers who don’t care what badge is on the hood. And for those who enjoy modifying their cars, the available twin-turbo V6 is worth a look. With typical turbo mods, such as a high-flow intake and exhaust, an upgraded intercooler, and an ECU tune, the 365-hp engine can be pushed to nearly 450 hp without even breaking a sweat.

2011 Infiniti M56

A Japanese Muscle Sedan

Infiniti hasn’t shown much interest in its sedan lineup for well over a decade, but not that long ago, the automaker offered some credible sports sedans. One of them was the fourth-generation M, launched in 2011 and renamed the Q70 starting in 2014. It came with two decent V6 choices, including one that formed part of one of the first performance hybrid powertrains, but anyone serious about speed would have to go with the range-topping V8 option.

The engine is a strong, naturally aspirated unit known for its smooth power delivery and impressive low-end torque. Because of its widespread use across a variety of Nissan and Infiniti models, there are many upgrades available for it. One of the most popular options is adding a supercharger, which can reliably deliver up to 500 hp.

2016 Jaguar XF S

The UK’s Aluminum 5 Series Fighter

The second-generation Jaguar XF is arguably the best sedan that nobody bought. It featured a lightweight aluminum chassis with standard rear-wheel drive and available all-wheel drive, all wrapped in one of the most handsome designs of any sedan from the past decade. It was launched for the 2016 model year and initially offered exclusively with a supercharged 3.0-liter V6, available in 340- and 380-hp outputs.

The latter was reserved for the XF S model, which also benefited from sportier tuning of the eight-speed automatic transmission, an improved suspension, and upgraded brakes. There are many modifications available for the engine, and one of the most effective is the various plug‑and‑play modules, which not only boost output but also improve the responsiveness of the throttle and transmission.

2008 Lexus GS 460

A Classic V8 Sports Sedan That Won’t Give Your Mechanic Nightmares

The third-generation Lexus GS arrived for the 2006 model year, and in 2008, its available V8 engine was upgraded from a 4.3-liter unit to a 4.6-liter powerhouse that delivered smooth, effortless acceleration. Today, the GS with the 4.6-liter V8 is still cheap, but prices have started creeping up, and anything with less than 100,000 miles comes with a steep premium.

While the V8-powered GS definitely leans more toward luxury than performance, a simple, effective way to improve the pace is upgrading the car’s intake and exhaust system. A high-flow air filter or cold-air intake paired with a custom exhaust improves airflow, increases throttle responsiveness, and can provide a modest boost in horsepower and torque. Anyone serious about performance will also want to upgrade the suspension, given the stock setup’s relatively soft tuning.

2018 Mazda 6

The Sleeper Of Sleeper Sedans

No one expects a Mazda6 to be a serious sports sedan, but the third generation offered some decent poke thanks to an available turbocharged engine that was added as part of a mid-cycle refresh. Unfortunately, opting for that engine meant a six-speed automatic transmission only. A manual was available, but it was limited to the entry-level naturally aspirated engine.

Common turbocharged engine mods such as cold air intakes and high-flow exhausts can help boost output from the Mazda6. And with the car being front-wheel drive, an owner may want to pair these upgrades with improved suspension and better tires to help put the power to the ground and make the car handle more confidently.

2010 Mercedes-Benz E550

Cheap To Buy But Not Cheap To Own

The fourth-generation Mercedes-Benz E-Class arrived for the 2010 model year, and before the AMG E63 showed up, the range-topping powerplant was a 5.5-liter V8 under the hood of the E550. Available with either rear- or all-wheel drive, it could also be optioned with an AMG styling package that gave the car the right look to match the muscle. With a 0-60-mph run of roughly five seconds, the E550 was quick then and still feels brisk today.

Better yet, that big V8 isn’t exactly working hard in stock form. While there are plenty of upgrade paths, the easiest and most cost-effective is a simple ECU tune, which can typically unlock an extra 15 to 30 horsepower without any other modifications. Just remember that maintenance costs on older Mercedes can be steep, so it’s smart to leave room in the budget for upkeep.

2008 Volvo S80 T6

Stealthy Speed From Sweden

Volvo’s second-generation S80 arrived in the US for the 2007 model year, showcasing a much more refined design than its predecessor, along with improved safety features and a luxurious interior that positioned it firmly in the premium sedan segment. While it debuted with an available V8 engine producing 311 hp, the turbocharged inline-6 in the T6 variant added for 2008 is a smarter choice today. Not only is it dirt cheap, but the powerplant is also a lot easier to tune on a shoestring budget.

As with most turbocharged powertrains, simple upgrades to the intake and exhaust can make a noticeable difference in performance. Doing it properly also means pairing these modifications with an ECU tune, and there are many plug-and-play options available that, together with the breathing mods, can deliver a meaningful increase in both horsepower and torque.

What Qualifies As A ‘Grandpa Sedan’?

It would be easy to add a ton of sedans to this list that are all easily modifiable to produce mega performance, but we’ve left them off for not being what we’d consider grandpa sedans. The Ford Taurus SHO is one such example. So what is a grandpa sedan? It’s very much a generalization, but it’s typically a sedan that is sedate and under the radar, often purchased by someone older who wants comfort and luxury, with a little speed, but in a very unassuming package. None of these cars look wildly sporty, and none of them really have the reputation for being true sports sedans. They’re effectively sleepers – unassuming but mighty.

Sources: Acura, BMW, Cadillac, Hyundai, Infiniti, Jaguar, Lexus, Mazda, Mercedes-Benz, Volvo