For over 40 years the BMW 3 Series has defined what it means to be a sports sedan. Responsive, refined, and with enough performance to go toe to toe with smaller and less practical sports cars, the 3 Series has satisfied the desires of many a car enthusiast, as well as many others who simply want to be seen driving the ultimate sports sedan.

All this popularity has unfortunately led to some softening in recent years, especially compared to the competition, which has been working hard to dethrone the king. Sure, the M3 is still the hard-edged track weapon that it has always been, but drive a more pedestrian 328i and you might start to wonder what all the fuss is about — especially after trying to tackle a sharp corner at speed.

Luckily BMW seems to have taken notice, and for 2016, the 3 Series gets some notable tweaks to help it fend off the competition. The aftermarket has also stepped up, with tuners offering packages to help owners wring the most performance out of their 3 Series.

I recently had the opportunity to test the new 2016 BMW 340i and thought it might be fun to run it side-by-side with a 3 Series that has been modified for extra performance. Luckily, the folks at Dinan were willing to loan us their 2012 328i with the S3 package, which features $10k in go-fast options. For anyone who doesn’t quite have the funds for an M3, or who doesn’t want to be quite so conspicuous, either of these cars could provide the perfect path to high-performance nirvana. Now all we need to sort out is which one is better.

The Cars

Perhaps the most notable change for the 2016 3 Series [F30] is the retirement of the 335i model, which has been replaced by the 340i. Luckily this isn’t just a meaningless badge swap, as the 340i gets a new inline 6-cylinder engine. Although it has the same 3-liter displacement as the outgoing engine, the new B58 engine is an all-new design, featuring all-aluminum construction and a redesigned twin-scroll turbocharger. Output sees a slight increase, with 320 horsepower and 332 lb-ft of torque now on tap.

In addition to the new engine, the 340i features a minor exterior styling update, with redesigned LED headlights that are spaced farther apart and a few other subtle changes. Our test car also featured the Track Handling package, which includes sports steering, M suspension, M Sport brakes, and 18-inch cast aluminum wheels with Michelin Pilot Super Sports at all four corners. Total price as tested is a not insignificant $58,420.

The Dinan S3 package can turn any ordinary 328i into a much more potent sports sedan, one that appears to be very competitive with the 340i, at least on paper. Modifications to the stock 2.0-liter 4-cylinder engine include the Stage 4 Dinantronics performance tuner, a Dinan high-performance dual core Intercooler, the new Dinan N20 big turbo kit, and a Dinan stainless steel free flow exhaust. This results in a substantial power increase over the factory rating. These are impressive numbers, even more so given how small the engine is.

The suspension also gains major upgrades, including a Dinan performance spring set and bump stops, Dinan lightweight tubular adjustable sway bars, and Dinan lower control arm monoball kit. Dinan also mounted a set of handsome 20-inch Dinan performance wheels with the same Michelin Pilot Super Sport tires as the 340i. Price for the Dinan N20 turbo wasn’t available at press time, but the bill for all these goodies is estimated to be around $10k, which when added to the price of a new 328i makes for a grand total of around $55k. The F30 328i has been in production since 2012, which means the price differential and savings become greater if you can find a certified pre-owned 328i in good condition and low miles.

Before moving on, I should mention that both cars came blessedly equipped with a 6-speed manual transmission, as any enthusiast would demand. Also, both cars were tested on a dyno, and let’s just say that the results are very intriguing. The new B58 engine turns out to be quite the overachiever, putting down 371 horsepower at 5,500 rpm and 378 lb-ft torque at 4,750 rpm, both substantially higher than the stated figures.

The Dinan 328i, on the other hand, managed 345 horsepower at 5,500 rpm, and 336 lb-ft torque at 5,250 rpm. While still impressive, this is somewhere between the 340i’s published factory spec and the measured output. The torque curve on the bigger 6-cylinder engine is also noticeably more flat. We also took the time to put each car on a scale, and here things tip back in favor of the 328i, which is a full 260 pounds. lighter than the 340i.

The Crew

In addition to myself and managing editor Derek Mau, we invited a few well-qualified guests to help us test the cars. Jeff Hecox has worked in the automotive industry for years and has extensive experience driving and working on cars. He currently works at Canepa Motorsports, the industry leader in buying, selling and restoring classic automobiles. Bill Clark has been a car enthusiast for years and has owned and tracked BMWs in the past, including an E36 M3.

For our test, we headed south to rural San Benito County, home of sprawling ranchland, rugged canyons, and mostly deserted backroads, all a mere hour drive from Silicon Valley. Each of us would drive each car several times on a few designated sections of road, which would hopefully ensure for a more objective comparison.

Driving Impressions

To begin with a simple observation, both cars are wickedly fast. Although we didn’t do an actual drag race, as that might have attracted too much attention, I would wager that it would be a very close finish. The extra power from the 340i’s larger engine is offset by the extra weight, although the flatter torque curve does give it a bit more midrange grunt. As Jeff observed, “The Dinan 328i didn’t have the low-end and mid-range torque of the 340i, but it pulled like a banshee in the upper end of the power band.”

In terms of handling, the lighter Dinan 328i with its modified suspension quickly impressed us with its cornering capability. As Bill enthused, “The 328i rips around corners, making the 340 feel pedestrian. It wants to be grabbed by the scruff of the neck and thrown around the corners, then taunts ‘Is that all you’ve got?’ I’d have to take the Dinan 328i to a track to really test its limits.”

This is not to say that the 340i handles poorly, it just feels heavier and less responsive. Jeff agrees: “In the lighter Dinan 328i, handling was noticeably better and more confidence inspiring than the 340i. If you kept in the power band, the Dinan 328i would accelerate between corners faster than the heavier 340i. Even in Sport–Plus mode the 340i felt a little over dampened and under sprung; it needs a performance spring set to take care of this.”

Unfortunately, we quickly discovered that the stock brakes on the 328i are less than confidence inspiring. Compared to the M Sport brakes on the 340i, the rotors on the 328i look tiny, as if they’ve been stolen from an economy car. Approach a sharp turn and you have to get on the brakes quite a bit sooner. However, as Bill pointed out, it doesn’t matter as much because of the superior handling: “I didn’t have to slow down as much for the corners because the handling was so good! The 340i’s brakes were better, but I needed them more to slow for the corners. Driving the 340i aggressively was: gas… BRAKE… turn… GAS… BRAKE… turn… Driving the Dinan 328i aggressively was: throttle… lift… turn, throttle… lift… turn.”

Verdict

Driving back to the South Bay in typical freeway traffic, I couldn’t help but marvel at how both of these cars provide very high levels of performance, but would also serve perfectly as a comfortable daily commuter. Choosing between the two would be tough, although preferences had definitely emerged.

We all agreed that the new engine in the 340i is a winner, and someone who values a more refined powertrain above anything else should probably go with the silky smooth 6-cylinder. But once you factor handling into the equation, the lighter, more nimble 328i easily makes a case for itself. As Bill summed up, “Outright, I prefer the Dinan 328 even with the 4-banger. I’d just start with a 328i with sport brakes, which may add some weight, but it would be equally distributed.”

Jeff seemed to be leaning towards the Dinan 328i also: “The Dinan 328i may not have the low-end torque of its 1000cc larger engine brother, but it will give you 3-4 mpg better gas mileage. Also, keep in mind that you can buy a pre-owned 328i all day long in the 20-25K range verses our tested 340i with an MSRP of $58k. That gives you a lot of room to modify your car with Dinan upgrades, and still keep your BMW warranty for the 4 years/50,000 miles.”

**Source: cars.com

The Dinan exhaust on the 328i does a magnificent job of bringing out the character of the turbocharged four-cylinder, but can it compare to the 340i and its inline-six? Watch the Rev Battle video below and let us know your thoughts.