As an enthusiast, the first thing that attracts you to a car is how it looks. If it is pretty or aggressive looking, you either think it is a beautiful car or it's a sports car. The next thing you think about is what's under the hood and this is very important, because a good-looking car needs the right engine to go with it. Did you know that the same engine that powers a $100,000 Porsche 911 GT3 can be yours for under $20,000—if you know where to look?With the changing automotive landscape, new cars with great engines that you used to love growing up are becoming expensive and rare. But when you look at the used car market, there are a lot of options, and you don’t need a six-figure bank account to own any of these engineering masterpieces. Some of the most iconic, soulful and responsive engines ever built are readily available for purchase and cost less than a new base model hatchback.Mazda RX-8 (2004-2010) - RotaryAverage Retail Price: $9,552MecumThe Mazda RX-8 is a beautiful Japanese sports car, and it has to be because it replaces the beloved Mazda RX-7 which is one of the most beautiful Japanese cars ever. The RX-8 is not just affordable, it is cheap compared to the rest on this list, not because it's less exciting than the others, but because it is a bit misunderstood. It was powered by Mazda's 1.3-liter naturally aspirated rotary engine but also makes less power than the twin-turbo RX-7. The most powerful variant made 232 hp and 216 lb-ft of torque, which is less than the base RX-7 at 255 hp and 217 lb-ft of torque.However, just like its predecessor, the RX-8's engine is smooth, revs higher than the RX-7 at 9,000 rpm vs 8,000 rpm, and unlike anything else you'll experience in this price range. Enthusiasts love it for its uniqueness, but it demands careful maintenance. This is not the easiest engine to live with, but just like the RX-7 it was part of the appeal. Where RX-7 prices have gone crazy, you can still find the RX-8 all day long for $10,000. For the money you feel like you're part of a niche club, one that values the excitement and quirks of this car. Acura RSX Type S (2002-2006) - K20 I4 Average Retail Price: $13,288 AcuraThe main reason you want this car is Honda's legendary K20 inline-four. This is one of those engines that punches far above its weight. If you loved the legendary DC2 Integra Type R, you'll get a similar experience with this car. It has a high-revving, incredibly durable, and tunable engine that has become a staple in the enthusiastic world. You see a lot of these engines swapped into other cars to make big power because it is just that good. But in stock form, they're still pretty good.There was a Type R version, but that never came to North America, but the RSX Type S still makes a healthy 200 horsepower and 142 pound-feet of torque. It still delivers the classic VTEC experience all the way to its 7,900 rpm redline. You can get a regular RSX for much cheaper but power drops significantly to 160 hp with a 6,800 rpm redline. Today, the RSX remains one of the cheapest ways to access one of the most beloved four-cylinder engines ever made. Scion FR-S/Subaru BRZ (2013-2019) - FA20 Boxer Engine Average Retail Price: $13,868 via Bring A TrailerThe Scion FR-S andSubaru BRZtwins aren't the cars you buy for power. It has a max output of 205 hp and 156 lb-ft of torque from it's 2.0-liter engine, but the Subaru boxer engine has built a loyal following. The flat-four in this car is mounted low in the engine bay and significantly lowers the center of gravity, transforming how the car handles. This is a momentum car and the engine rewards that style of driving instead of straight line speed, which is exactly why enthusiasts respect it. On a twisty road, it can easily keep up with more powerful V6 cars.This is also one of the most mod-friendly platforms out there. Turbo kits, engine swaps, and tuning options are everywhere. Want to build a time attack car or drift car? They've already been done with this platform, making it a blank canvas for enthusiasts who want to build something personal at an affordable price. Infiniti G37 (2009-2013) – VQ V6 Average Retail Price: $14,254 Via: Infiniti The Infiniti G37 easily flies under the radar, but enthusiasts know exactly what it offers. It uses the same beloved VQ engine Nissan has been using in the Nissan 350/370Z. It uses the updated VQ37VHR V6 engine found in the Nissan 370Z with 330 hp and 269 lb-ft of torque. This engine line has earned a reputation for strong performance, reliability and that distinctive trumpet exhaust note. You can have this as a coupe or sedan and they both come with the VQ engine. It’s not the lightest or most agile car here, but as a daily driver with real performance, the G37 hits a very sweet spot for any enthusiast. Ford Mustang (2011-2014) - 5.0 Coyote V8 Average Retail Price: $14,500 Bring a Trailer Now we step into some powerful cars with V8 engines, and we start with the Ford Mustang's V8. This was when Ford introduced the 5.0-liter Coyote V8, and it started making some serious power. It initially made 412 hp and 390 lb-ft of torque but in 2013, power was bumped to 420 hp. Now the Mustang finally had an engine that could compete globally and make power throughout its rev range and not just in a straight line. It also has a great exhaust note and can easily make more power.This Gen 1 Coyote engine isn't as boost friendly as the latest Gen 3 and 4 engines. But with a simple bolt-on supercharger, you can easily make 600+ horsepower for around $20,000 all in. This is why it remains a favorite among enthusiasts who want power and reliability without complicated setups. Chrysler 300C (2011-2018) - Hemi V8 Average Retail Price: $14,660 Bring A TrailerThe Chrysler 300C might look like boring, comfortable cruisers, but beneath that lies the legendary HEMI V8. This is the same 5.7-liter Hemi found in the Dodge Charger/Challenger but slightly detuned but still making a healthy 363 hp and 394 pound feet of torque. Since this was made to be a luxury car, smooth power delivery and a quieter ride were the aim, but with that unmistakable V8 rumble. When you put your foot down, this engine never feels dull. With a budget of around $15,000, you can get a later 2017-2018 models with the updated looks. This is the car for buyers who want muscle car character in a more practical package and it’s a surprisingly compelling option. Chevrolet Camaro SS (2010–2015) - LS3 V8 Average Retail Price: $16,750 Chevrolet The fifth gen Camaro SS is a great car with one of the best V8 engines in the industry. Chevrolet’s LS engines have built a strong reputation for reliability, simplicity, and good tuning potential. But you have to make a choice between two powertains for this specific model. The first is the LS3 V8 which makes more power at 426 hp and 420 lb-ft of torque, but is only available with a six-speed manual transmission. The second engine is the L99, producing 400 hp and 410 pound feet of torque with a six-speed auto. But the LS3 is the more tunable engine and is one of the easiest ways to access serious V8 performance on a budget. It remains a go-to platform for both beginners and experienced builders. Porsche Boxster (2005-2008) - Flat Six Average Retail Price: $19,120 Porsche The idea of a cheap Porsche feels slightly ureal but the Boxster makes that possible. But why would you want a Boxster in the midst of these heavyweight V8 powerhouses? First off, it's a Porsche, so it drives really well, but the main reason is the naturally aspirated flat-six. Car enthusiasts rave about the flat six in GT3 products, but those are pretty expensive. However, you can get an almost similar experience with the mid-engine Boxster.The Boxster originally came with two engines, a 2.7-liter and 3.2-liter flat six, It later received a larger and more powerful 3.4-liter flat six in 2007. These engines are smooth, responsive, and deliver an engaging driving experience that feels far more expensive than the car’s current price suggests. Add a full aftermarket exhaust system, and you're 80% close to the sound of a GT3. Maintenance can be a concern not because it is unreliable, but because it is a Porsche. For enthusiasts willing to do their homework, the payoff is one of the most engaging driving experiences available on a budget. BMW M3 (2008-2011) - S65 V8 Average Retail Price: $20,503 Via: Bring A TrailerThe E90/E92 BMW M3 stands out for one big reason: its S65 V8. The BMW 3-series as a whole has been defined for its smooth inline-six engines. This generation is the only time the M3 got a V8 before switching to the turbocharged inline-six engines. The S65 V8 is a standout engine for this generation, a naturally aspirated, exotic-sounding 4.0-liter V8 producing 414 hp and 295 lb-t of torque revving to 8,400 rpm. The power delivery is just as smooth, linear and almost addictive.The M3 was available as a sedan (E90), coupe (E92), and a convertible (E93). The coupes are easily available while the sedans are the rarest, making it hard to find. It's not the cheapest car to maintain—you may have to do some preventive maintenance to make sure your M3 will be reliable, and that's partly why values have softened in some markets. But from an engine perspective, it’s one of the most special M cars ever made, and we know it. Mercedes-Benz E63 AMG (2007-2009) - M156 V8 Average Retail Price: $20,544 via Bring A TrailerThe Mercedes-Benz E63 AMG hides one of AMG’s most iconic engines under a relatively understated body. The M156 is an engine you'd associate with the W204 C63 AMG but this E63 had it first, and it has more power. In this car, it makes 507 hp and 465 lb-ft of torque; the original C63 had 451 hp and 443 lb-ft of torque. This is a brutal naturally aspirated V8 that is full of charcoal similar to most American V8s.A comparable C63 would be hard to find in this price range, this is cheaper and offers the same experience. It’s an engine that doesn’t just move the car, it dominates the entire experience with its sound and raw delivery. This is my personal favorite pick and for the price these cars go for today, it’s hard to think of another sedan that offers this level of performance and presence.Sources: Classic.com, JD Power, OEM Manufacturers.