The BMW B58 engine is a turbo 3.0L inline-6 that was first introduced to BMW models in 2016. It manages a respectable 322-382hp and 332-369 lb-ft from the factory. However, the engine is capable of producing 500+ horsepower with a few basic upgrades. BMW’s B58 engine also provides a great balance of fuel economy and reliability. There’s a reason Toyota opted to use the B58 3.0 turbo in their legendary Supra.
Ultimately, this 3.0L inline-6 BMW engine has a lot to offer. There is also a lot to unpack when it comes to the B58. How reliable is the engine? What are the best B58 upgrades to make 500+hp? How does it stack up against other BMW engines like the N54, N55, etc? In this guide, we discuss BMW B58 engine specs, performance, upgrades, reliability, and more.
B58 Engine Specs
Specs for the B58 engine are as follows:
|Fuel System||Direct Injection|
|Engine Block||Aluminum, closed deck|
|Valvetrain||DOHC, Valvetronic, Dual VANOS|
|Bore x Stroke||82mm x 94.6mm|
|Compression Ratio||11.0 : 1|
|Torque (lb-ft)||332-369 TQ|
Most engine specs for the B58 are standard for modern turbo BMW engines. The N54 was released in 2007 with a similar 3.0L turbo inline-6 design utilizing direct injection and dual VANOS. It was BMW’s first mass-production engine to combine all of this technology. Since then, the very basic design has remained much the same. The B58 engine is also a 3.0L inline-6 turbo engine with direct injection and dual VANOS. BMW also implemented Valvetronic (variable valve lift).
BMW also switched from an open-deck block design to a closed-deck block. This design is great for strength at high power and boost. Compression is up from 10.2:1 on the N54 and N55 to 11.0:1 on the B58 3.0 turbo engine. All of these specs allow the B58 to produce up to 382hp and 369 lb-ft in the newest B58B30O1 engine.
It’s also generally accepted that BMW underrates their engines from the factory. The B58 horsepower rating is actually closer to what it puts down to the wheels (albeit, on a dynojet which generally reads on the generous side). Anyway, the real appeal to the BMW B58 is its immense potential with simple upgrades and bolt-on mods. The engine is very tuner-friendly and we’ll circle back to this topic later in the article.
B58 Technical Update (B58TU)
One important subject regarding the B58 engine is the technical update in 2018. These engines are identified with an engine code ending in “1” and include the B58B30M1 and B58B30O1. For short, the updated engine may be referred to as the B58TU or B58TU1. A few notable changes to the B58TU include:
- Higher-pressure fuel system
- Re-designed timing chain
- Updated cylinder head (integrated manifold)
- Particulate filters
A few of these changes help enhance performance while others are aimed at small reliability and emissions improvements. One major performance upgrade is the new 350 bar fuel system (vs 200 bar on the older B58). This higher pressure fuel system allows higher E85 mixtures, and supports more power before fueling mods need to be addressed.
We could spend a long time discussing all of these changes of the B58 vs B58TU. However, there’s still a lot to cover in this article. If you’re interested in learning more about this topic, check out this detailed B58 vs B58TU article.
BMW B58 vs N55
The B58 is the successor to the N55 engine which makes the N55 vs B58 a popular topic. Both engines share the same 3.0L inline-6 turbo design. They’re also in similar models despite BMW’s re-badging (with the release of the B-series engines the 40i badge essentially replaced the 35i). Anyway, a majority of the B58 vs N55 similarities end there. BMW went in a different direction with many of the design aspects.
A few notable differences are the air-to-water intercooler, closed deck block, forged steel crankshaft, and a 5,000 PSI HPFP. Again, these are just a few examples of the many differences between the N55 vs B58. We chose those few changes to highlight one primary point – the BMW B58 is the stronger, better performance engine. Specs on paper don’t paint the full picture, but this does hold true in the real world too.
BMW N55 engines are generally capable of about 400-425whp on the stock turbo. Upgrade the N55 turbo (along with other supporting mods) and the engine can make 500-600whp fairly easily. Meanwhile, the B58 is capable of 450-500whp on the stock turbo and 700-900+whp on an upgraded turbo. It’s only fair to note that a number of N55’s have eclipsed 750whp. However, the N55 doesn’t make that power as easily as the B58.
Ultimately, the N55 vs B58 is an interesting comparison. They’re both great engines, but the B58 is certainly an improvement over the N55. Not only does it offer better factory performance and overall potential, but the B58 is also the more reliable engine. More on reliability for these engines in a few moments. For now, let’s compare the B58 to another BMW engine that may be a more formidable opponent.
N54 vs B58
Ahh the “legendary” BMW N54 engine. If this engine isn’t legendary for its incredible performance then it’s likely known for its troublesome (at best) reliability. The N54 dropped in 2007, nearly a decade before the B58. It boasts the same 3.0L inline-6 design, but goes a step further with twin turbochargers. As with the B58, the N54 features a strong forged crankshaft. However, the open-deck block is a drawback to the N54.
That didn’t stop the N54 from making 450-500+whp and 550+wtq on stock turbos. Upgraded twin turbos can push 600-700+whp while single turbo conversions have broken the 1,000whp mark. Plenty of stock internal N54’s have held up very well at 650-700+whp. Time will tell if the B58 holds up as well in the long-run but all signs are green thus far.
The N54 is an excellent performance engine, especially for its time. However, time and technology has caught up and the B58 seems to be right there with the N54. Except BMW did a much better job with overall design and reliability with the B58. While the N54 is a great engine it did have a lot of early troubles with reliability and engine problems. BMW took a step back from performance with the N55 to improve reliability. Then, they tied it all together with the BMW B58.
BMW B58 Reliability & Problems
Discussing reliability and engine problems on a relatively new engine is a tough topic. The BMW B58 is still only 6 years old and that’s not quite enough time to gauge long-term reliability. However, the B58 is proving to be a reliable engine so far. Some claim it’s reliable by “BMW standards” but we believe the B58 delivers good reliability by any standard.
Again, even Toyota is using the B58 3.0L turbo engine in their newest Supra models. They’re generally among the highest reliability standards. Toyota did do reliability and longevity testing on the B58, and supposedly made some small changes. Whether or not those changes were passed along to the B58 installed in BMW’s isn’t fully known.
Regardless, the B58 is shaping up to be a great engine. Circling back to the N54 for a brief moment, the engine had plenty of flaws that were evident within the first 2-6 years. The B58 hasn’t had that. Despite reliability concerns of the N54 it still delivers phenomenal internal reliability. The entire cylinder head, rods, rod bearings, pistons, rings, etc. are nearly bulletproof at stock power levels. BMW’s timing chain is also excellent.
It isn’t uncommon to see these engines eclipse 250,000 miles. They’re just expensive to get there due to other problems like oil leaks, coolant leaks, water pump failures, carbon build-up, fuel injectors, etc. The B58 should be capable of the same longevity without nearly as many ancillary system issues.
Here’s a video produced by us that goes over the BMW B58 Common Problems, or continue reading below:
B58 Engine Problems
With the reliability and longevity topic out of the way let’s take a deeper look at BMW B58 engine problems. What are some potential flaws to look for in the B58? Are there any existing issues that appear common? Again, as a 6 year old engine we don’t yet have the full picture. However, it’s easy to point out a few areas based on the limited data combined with common BMW engine problems in the past. A few things to look out for on the B58 include:
- Coolant loss
- Oil leaks
- Carbon build-up
Below we’ll quickly dive into each of these potential B58 problems for further review. None of these issues are truly common in that they affect a lot of B58 engines. Instead, when things do go wrong these are a few of the most common areas.
1) BMW B58 Coolant Loss
Due to the air-to-water intercooler, the B58 actually uses two coolant tanks and systems. There are a number of reports of low coolant levels in the main tank. Some also report low coolant in the secondary tank (for the air-to-water intercooler), but to a lesser degree. Anyway, we don’t believe B58 coolant loss is a major concern as of now.
B58 coolant loss has not been linked to any specific cause or underlying problem(s). The cooling system is a pressurized, air-tight design so coolant loss shouldn’t occur naturally. However, the coolant cap is designed to vent pressure in the case of over-pressurization. It’s possible the B58 3.0L inline-6 coolant caps simply aren’t tight enough.
That’s our best guess for now since there aren’t any common issues related to this mysterious coolant loss. It’s something to monitor as the B58 ages, but it’s not a major concern as of now. Of course, if you’re noticing overheating, visible leaks, or coolant/oil mixing, then there’s likely another issue going on that needs further diagnosing.
2) B58 3.0 Inline-6 Oil Leaks
It’s no secret that BMW’s are prone to oil leaks. The N54 and N55 both had frequent issues with oil leaks from the valve cover gasket, oil pan gasket, oil filter housing, and a few other areas. A number of BMW B58 engines are already running into similar oil leaks. However, they appear to be much fewer and further in between.
However, all cars are prone to leaks as they accrue age and mileage – and it’s not just BMW. As such, it’s likely B58 oil leaks become more and more common as these cars continue aging. Most oil leaks are cheap gaskets that you can pick up for $10-50. Labor is the real killer, though. A B58 valve cover gasket costs about $50, but with labor it can easily end up in the $800-$1,200+ ballpark.
Sticking with the trend, the B58 seems to be much less problematic than former BMW turbo engines. We doubt oil leaks will be as common as the N54 or N55, but it’s still something to consider as the B58 ages.
3) 3.0L Turbo Carbon Build-Up
Carbon build-up is a hot topic when it comes to gasoline direct injection engines. All engines produce some natural oil blow-by that makes its way into the intake tract. It then sticks to intake valves and ports. Traditional port injection sprays fuel into the ports, and detergents in gasoline naturally wash away any deposits.
Direct injection sprays directly into the cylinders, so there is no fuel to wipe away deposits. The deposits eventually form carbon build-up which can cause misfires, power loss, and other performance issues. The N54 generally needs intake valve cleaning after 60,000 to 80,000 miles. The N55 was a decent improvement and can make it 80,000-100,000+ miles before carbon build-up is severe. We suspect the B58 is a further improvement.
Walnut blasting is a common method to remove carbon build-up. It requires removal of the intake valves and is a few hour process that can cost about $400-700. Many BMW shops charge significantly more as we’ve personally heard numerous quotes of $1,000+.
Anyway, carbon build-up isn’t a serious issue. It rarely presents any major threats to reliability or longevity. However, carbon build-up can cause annoying performance and drivability issues. Time will tell how well the B58 handles carbon build-up. Chances are, B58 walnut blasting will eventually be good maintenance. Hopefully it’s only every 100,000 to 125,000+ miles, though.
Best B58 Performance Upgrades
Alright, we’re finally moving onto what is – in our opinion – the most exciting topic about the BMW B58 3.0L turbo engine. As mentioned a few times, the B58 is a very strong engine capable of making lots of power with simple upgrades. Some of the best B58 bolt-on mods include:
- Fueling / WMI
In this article we’re sticking with some of the easiest power mods for stock turbo B58’s. They’re among the best first upgrades for the 3.0 inline-6 turbo engine. There are tons of upgrades available for the B58 since it’s a very tuner-friendly engine. The engine can accomplish a lot whether you’re looking for a “modest” 400-500whp on the stock turbo or a crazy 800+whp build.
There’s a lot to cover when it comes to turbo upgrades and other serious mods. As such, we’ll address more of this in future articles. For now, let’s jump in and discuss some of the best, simple bolt-on upgrades for the BMW B58.
1) BMW B58 Tuning
A tune is the single best performance upgrade for the B58. Not only does tuning offer massive power gains, but it’s also the foundation to making more power with other bolt-on mods. With standard pump fuels, a tune alone can offer gains in the 40-70whp ballpark. Add in an E85 mixture and a tune can offer gains of 70-100+whp. That’s a lot of power for a simple $500 tune.
Among our favorites is the Burger Motorsports JB4. This piggyback tune is simple to install and offers 9 different maps for various goals and needs. Unlike flash tuning, there’s no need to re-flash the DME. You can switch from the factory tune, to kill mode, to a valet/low boost map in a matter of seconds. It also supports water-methanol injection, E85 mixes, back-end flash tuning, and much more.
Ultimately, if you’re looking for one single performance mod for the B58 then it’s hard to go wrong with a tune. The below dyno shows the baseline for a 2020 Z4 at 400whp, and a whopping 490whp with the JB4 tune and E40 fueling. Impressive power gains at the least.
Power Gains: 40-100+whp
Buy Here: BMW B58 JB4 Piggyback Tune
2) B58 Performance Intake Mods
An intake doesn’t offer nearly as much power or performance as the rest of the upgrades on this list. However, it’s still a great B58 bolt-on mod that’s cheap and easy to install. It’s also an essential upgrade to making more power. Of course, as you increase boost and power then the B58 requires more airflow.
The simple goal of a performance intake is to flow more air efficiently. Look no further than an open intake system to maximize performance. With just a tune, an intake might only pick up about 3-5whp. However, the benefits of a B58 intake upgrade increase as you add additional mods and more boost. Power gains of 7-10+whp are possible. Additionally, intakes offer awesome sounds, a clean engine bay, and a number of other benefits.
Burger Motorsports has some great intake options for tons of B58’s including the Supra, F chassis, and G chassis models. Regardless of the intake you choose, it’s an awesome mod to combine with a tune for the added performance and sounds.
3) BMW B58 Downpipe Upgrades
Outside of a tune, downpipe upgrades are our favorite bolt-on mod for turbo engines. The B58 downpipe bolts directly to the turbocharger and within resides a restrictive particular filter or catalytic converter. While great for emissions these parts are highly restrictive when increasing power and boost.
A B58 catless downpipe can offer gains in the ballpark of 20-30whp. It also improves turbo spool, engine/exhaust sounds, and more. The main concern is the legality of a catless downpipe. As such, catted downpipes are a popular option. They don’t offer quite as much performance, but should allow the B58 to pass emissions testing in most states. Expect power gains of about 10-20whp with a high-flow B58 catted downpipe.
Whether you’re looking for a catted or catless option VRSF has you covered. The catless downpipe for the F chassis M240i, 340i, 440i, 540i, 640i, and 740i is $299.99 while the high-flow downpipe is $479.99. We believe VRSF offers some of the best bolt-on upgrades for modern BMW engines, so look no further.
Power Gains: 10-30whp
Buy Here: BMW B58 VRSF Downpipe Upgrade
4) 3.0L Turbo Fueling & WMI
Fueling and water-methanol injection (WMI) could be an entire article of its own. As such, we’ll stick with some speedy notes to keep things moving. The B58 loves high-octane fueling when increasing boost. Normal pump gas is convenient, but it doesn’t deliver the best performance or power. Enter E85, race gas, and WMI.
In our opinion, E85 is the ultimate fueling solution. It burns cooler than gasoline and has a lower stoic. It greatly reduces the chance of pre-detonation, which means better ignition timing, more boost, and a lot more power. The downside to E85 is that it contains less energy per part when compared to gasoline. In turn, you need to flow more fuel which puts a lot of stress and demand on the fueling system.
The original B58 engines can handle about 20-30% E85, and the B58TU can handle about 30-40% on the stock fuel system and turbo. As shown in the dyno above, even a 40% E85 mixture can offer tons of power. Other great fueling alternative are race gas and water-methanol injection as they don’t put extra demand on the fuel system.
B58 Bolt-On Upgrades Summary
A tune, intake, downpipe, and better fueling can take the B58 a long way. These mods can push the B58 into the 450-500whp ballpark. That’s a lot of power for a 3.0L inline-6 engine on a factory turbocharger. Generally, the B58 can tolerate that power without serious reliability or longevity concerns.
It doesn’t stop there, either. The BMW B58 is capable of 600-700+whp on the stock engine with additional fueling mods and turbo upgrades. However, there are a lot of other mods to consider when shooting for that kind of power. It’s not for the faint of heart, but the B58 is a highly capable engine that can deliver immense power.
BMW B58 Engine Summary
The BMW B58 is a 3.0L inline-6 turbo engine that succeeded the popular and successful N54/N55 engines. It powers many flagship models like the BMW M240i, 340i, 440i, Z4 40i, and plenty more. With 322-382 horsepower from the factory the B58 delivers great performance. However, the great reliability (so far) and aftermarket potential is what really sets the B58 apart.
In its young age, the B58 is proving to be a reliable engine. There haven’t been any glaring issues or problems that appear very common. However, coolant loss, oil leaks, and carbon build-up are a few potential issues to monitor as the B58 ages. Regardless, the B58 is shaping up to be a reliable engine not only by BMW standards, but by any standards (including Toyota who is using the B58 in their Supra).
Those looking for extra power and performance won’t be disappointed in the BMW B58 3.0L engine. A few simple bolt-on mods can push the B58 to 450-500+whp on the stock turbo. If that isn’t enough there are already plenty of B58’s pushing 700+whp, and this platform still has a lot of growth and potential left.
What’s your experience with the B58? Are you considering one?
Leave a comment and let us know!