335i vs 340i Performance Reliability

BMW 335i vs 340i – Performance, Tuning, Reliability

About Zach Mayock - DieselIQ

Meet Zach

Zach is a BMW enthusiast with a passion for performance. With over 10 years of experience modifying and performing DIY work on BMWs, he’s developed a deep understanding of virtually every BMW engine. He’s also the proud owner of a 600whp N54 with upgraded twin turbos and an E30 325i drift car and has a particular affinity for the S58 engine. Zach is highly knowledgeable about all things BMW, but his expertise in tuning and performance mods sets him apart. His experience as an enthusiast, combined with his technical knowledge, makes him an essential resource for anyone looking to improve the performance of their BMW.

In 2016, BMW made a change to the badging of certain models. Most 28i models began carrying a 30i badge while 35i models went to 40i. These changes occurred at the same time BMW released the new B58 engine. In short, the 340i is simply the newer version of the BMW 335i. Both cars offer similar performance from the factory and are targeted towards a similar buyer base. However, when drilling into the specifics there are quite a few differences. In this article, we discuss the 335i vs 340i and compare performance, handling, tuning, and reliability.

335i and 340i

Quick Background Info

The 335i and 340i models span several chassis generations and engines:

  • 2007-2010 E90/E92 335i (N54 engine)
  • 2010-2013 E90/E92 335i (N55 engine)
  • 2013-2015 F30/F32 335i Sedan/435i Coupe (N55 engine)
  • 2016-2019 F30 340i (B58 engine)
  • 2016-2020 F32 440i (B58 engine)
  • 2019-present G20 M340i (B58TU engine)

The E90 sedan and E92 coupe were both badged as the 335i. When BMW released the F chassis in 2013 they re-branded coupes as the 4 series.

As you can see, there’s a lot to unpack if we look at all of the available 335i vs 340i models. Each have spanned 2 chassis generations and the older 335i models feature both the N54 and N55 engine while newer 340i models receive the B58 or updated B58TU.

Most likely aren’t considering the extremes, such as 2007 E90 335i vs 2021 G22 M440i. We’ll make some references to most models to tie this whole comparison together. However, our primary focus here is the the F-chassis 335i vs 340i.

BMW 335i vs 340i Looks

Looks are subjective, so we’ll be pretty quick on this topic. Again, we’re primarily focusing on the F30/F32 chassis for the purpose of this article. That said, as both the 335i and 340i are built on the same chassis they share very similar looks. However, BMW did facelift the 2016 models along with the release of the new B58 engine. The facelift versions are known as LCI.

Updates were fairly minor, but did include the headlights, tail lights, new color options, and some small interior changes. To the untrained eye both the pre LCI 335i and LCI 340i look nearly identical. However, side by side you might notice the 335i vs 340i sport slightly different looks.

We think they’re both good looking cars and wouldn’t have a huge personal preference.  Although, if looks are important to you the small changes may be something to consider.

335i vs 340i Performance

This will be another fairly quick topic. We’ll discuss the bulk of 335i vs 340i performance in the Tuning section. In reality, the 335i vs 340i deliver very similar real world performance. On paper, the 340i is a little quicker thanks to a small boost in power and torque. The 335i with the N55 engine offers 300hp and 300tq while the 340i comes in at 320hp and 330tq. BMW 340i models with the B58 also have the advantage of a slightly better power curve.

0-60 from the factory is nearly identical right around 5.0 seconds. 1/4 mile times come in the mid 13’s around 105mph. Various testing shows different results, and there are many factors that affect these times. Tires, road conditions, altitude, transmission, AWD or RWD, and drivers are some important factors. Point is – the 335i vs 340i offer similar performance from the factory.

335 vs 340 Handling

Once again, the F30 335i vs F30 340i offer similar handling. However, the 340i does have a slight edge thanks to some updates from BMW. They changed the suspension geometry, re-designed the electric power steering, and updated the rear dampers and stability control. This helps the 340i put down better numbers on the skidpad.

Our one complaint about both F30 models is the electric power steering. It simply doesn’t offer the same feel and feedback as BMW’s older power steering. The electric assistance just takes some of the joy out of it. Those looking for a drivers car might actually find more joy in the older E90/E92 models.

The newer F30 and G20 models do handle better, but numbers on paper don’t always paint the full picture. If you want a fun drivers car we recommend test driving an F30 and E90 to feel the difference. Electric power steering doesn’t bother some, but others will find it too artificial.

N55 vs B58 Tuning Potential

This is where the 340i begins to pull out ahead of the older N55 engine in the 335i. BMW opted for a closed-deck block and stronger overall engine design. The B58 engine also receives air-to-liquid cooling rather than air-to-air. It helps prevent heat soak in the 340i and leads to a more consistent power and performance feel.

A note in advance – the N55 in the 335i is by no means a bad engine. However, the B58 is simply the better engine. It’s a stronger engine design with a better factory turbo and cooling setup. It makes sense given the B58 is the newer engine and time allows for greater advancements. One exception is arguably the older N54 powered 335i models. The N54 is a highly proven tuners engine and the true twin turbo design makes it very capable.

335i vs 340i Full Bolt-Ons

With full bolt-ons (FBO) the N55 335i and B58 340i offer respectable power gains over stock output. The B58 in the 340i is the more capable engine, though. A stock turbo 340i can be pushed to about 450-500whp whereas the N55 335i tops out around 400-425whp. If performance is the goal you’ll want to stick with the F30/F32 335i since it uses the EWG turbo setup. The older N54 is capable of about 450-500whp on the stock twin turbos.

Many owners will likely be happy with 400whp, but the N55 will be more costly to push any further. An upgraded turbo will be required to go much further and that can be a costly install. Here are a few guides to bolt-on mods for the F30 335i and F30 340i.

N55 400whp Guide

B58 500hp Guide

N55 vs B58 500+WHP

Those with crazy horsepower goals will find it easiest with the B58 powered 340i. Tuning and aftermarket development takes time, so the newer B58 is at a disadvantage. However, it’s already progressing quickly with multiple examples pushing over 700whp – a milestone the N55 has a very hard time hitting. The B58 is also the stronger engine internally, and is better suited to handling 500+whp.

If you’re considering the extremes, an N54 335i is a great buy if you want 700+whp. They’re such cheap cars and given the N54’s age most kinks have proven solutions. Countless N54’s are making a modest 450-600whp on upgraded twins. Then there are plenty of single turbo builds making 700+whp and even a few over the 1000whp mark.

Of course, the N54 is old and has some reliability concerns. It’s still considerably cheaper to build a 700whp N54 compared to the N55 or B58. We’d take the N54 335i over the N55 335i or B58 340i for 500+whp builds, but the B58 is a very close second.

BMW 335i vs 340i Reliability

Many people are familiar with the reliability horror stories of the original N54 powered 335i models. The 335i was a new direction for BMW. It was the first mass production turbo, direct injection engine from BMW. There were kinks to work out, and it took some time. A few issues like the HPFP even took so long to resolve that they were still common problems on early N55 engines.

The later model N55’s show a solid improvement in reliability, though. However, the 335i N55 is still prone to its fair share of problems. Valve cover gaskets, oil pan gaskets, VANOS solenoids, and the cooling system are among those.

BMW also went a new direction with the 340i B58 engine. It’s a modular engine that shares many parts with the smaller 2.0L B48 engine. The B58 is basically the same engine with 2 extra cylinders. This helped BMW cut part costs and focus on reliability. So far, it appears to be a good strategy as the B58 is shaping up to be a reliable engine (relative to BMW). It’s also a newer engine so age works to its advantage. Time will tell if the B58 is prone to more issues that aren’t showing up in bulk yet.

BMW N54 Common Problems

N55 Common Engine Problems

BMW B58 Common Problems

BMW F30 35i vs 40i Summary

There are plenty of other minor differences we didn’t cover in this article. However, the 340i is the same car as the 335i in many ways. They’re both intended for the same target market and share many things in common. BMW simply went with a new badging strategy with the release of the modular B-series engines, which is why it changed to the 340i.

BMW 335i and 340i models both sit upon the F30 chassis, but BMW facelifted the 340i models. To the untrained eye the cars look very similar, but some may prefer one design to the other. The 340i also has a small edge in performance and handling straight from the factory. However, the real benefits of the B58 340i engine are seen in the aftermarket. It’s simply the more capable engine. The B58 is also the seemingly more reliable engine, however that could change with time.

Some might also consider the newest G20 M340i models, which come with a hefty price tag. The B58TU is a great engine and the M340i offers next level performance, though. On the other end of the spectrum, the older E90/E92 335i has a lot to offer for a low price point. Though, age and reliability are two big concerns in going with the older N54 or N55 PWG engines.

Are you considering a 335i or 340i? Which do you prefer?

For more info on these cars, check out some additional guides including our E90 Buyer’s Guide, F30 Buyer’s Guide, and What Year 335i You Should Buy.

Drop a comment and let us know!

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  1. Great article. Had an n54. Want to buy another one but the cars are too old. As they age, any car’s plastic and rubber hose start failing

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