With the launch of an all new 2013 Porsche Boxster S, BMWBLOG figured it would be a good time to compare its natural rival: the BMW Z4 sDrive35is. An unfair comparison you say? Both two seat German droptops can be well optioned for just under $70,000, and both rear-wheel drivers can get you from 0-60 mph in about 4.8 seconds. However, both provide a rather different driving experiences and get you there in rather different ways via divergent philosophies.

BMW kept the faithful hoping an M model would come out in this the second generation of the E89 Z4. After all, BMW had given us an M-version in its previous two roadsters – a Z3 M and an E85 Z4 M with the fantastic screaming S54 motor from the E46 M3. I saw an E85 Z4 M just the other day and they still look fantastic. They were also quicker than the Boxsters of its day. Plus the BMW had a Limited Slip Differential (LSD) where as the Porsche car didn’t. Alas no M Z4 was to come. However, in 2011 BMW chose to give us a souped-up hot rod Z4 sDrive35is with a tweaked N54 twin-turbo motor with a new over-boost torque feature and no LSD but lots of electronic handling aids.

The original Boxsters were much maligned in the automotive press and never the sales success Porsche wanted, even with a technically superior mid-engine layout. Sabine Schmidt, a Nurburgring phenom, racer of both BMWs and Porsches dismissively calls the old Boxster a “housewife’s car.”

In fact it wasn’t until 2011 with the stripped down track oriented Boxster Spyder that the press outside of dedicated Porsche magazines gave it much positive press. This though, has all changed with the third generation and all-new 2013 Boxster which sports Porsche’s internal code 981. In person, as in photos, it looks absolutely stunning. The automotive critics are all aglow in their reviews of it and after driving it I agree. Even Chris Harris declares the 2013 Boxster S a “proper sports car,” and “Porsche has finally built a Boxster that a man could buy” and “I don’t feel self conscious driving it.”


Here we see a major divergence in philosophy between Porsche and BMW. Both are Direct Fuel Injected motors, however now BMW has chosen to put a turbo on nearly everything. The last naturally aspirated engine BMW sells now is the V8 in the E92 M3. When this M3 is retired in 2013, the high-revving naturally-aspirated motor and the core founding philosophy of BMW M will be sadly gone. The BMW power unit maintains a high output – 332 lb-ft from 1,500 rpm to 4,500 rpm. Maximum output of 335 hp is delivered at 5,900 rpm.

Porsche, though, offers a high-revving naturally-aspirated engine in the Boxster but turbo charges their top of the line models. When looking at total output of the the two motors, BMW wins here because it brings 100 more ft/lbs of torque to the fight. The Porsche does get a nod though for engine place being in the middle of the Boxster instead of the “wrong end” like a 911.

Winner: BMW


Porsche offers a 6-speed manual standard, and their PDK double clutch is a $3,200 option. The BMW Z4 sDrive35is comes in one transmission only – the DCT. Both offer paddle mounted shifters and having driven both the DCT and the PDK, I actually prefer the paddles on the Porsche. However, both work well and are intuitively placed. The ability to use three pedals to shift yourself, even though slower, is more involving and you save $3,200, so it tips this round in favor of the Porsche.

Winner: Porsche


Base price for the Z4 sDrive35is is $64,200 and the one I drove had a MSRP around $68,000. The base price of the 2013 Boxster S is surprisingly less at $60,900. Granted the Porsche doesn’t come standard with the double clutch gearbox and if you add $3,200 to get it, the cost differential nearly evaporates. However, if you start to go crazy with the options on the Porsche, the price can shoot up easily into 911 territory. Just out of curiosity I started clicking every option available on the 2013 Porsche’s Boxster S’ configurator and jacked the price up to $103,535 before I got bored and quit. Nuts huh? Tie if you can control yourself on the options list for Porsche or BMW is the winner if you cant.

Tie: BMW / BMW


The 2013 Boxster is so new, there aren’t any racing versions of it. If you ever go to a Porsche Club or other amateur race, you’ll find that quite a few Boxsters are out on track, way more than Z4s raced at amateur racing in the US. There’s a but here for BMW. Munich has factory Z4 GT3 race cars in Europe, and they look damn and I mean damn good. Much better than any Boxster race car I’ve ever seen. They are available for purchase but there’s a downside though, they cost $340,000 Euros +VAT. The Z4 GT3 makes up for it with a 4.4 liter V8 with a 9,000 red line and pumps out 515 bhp with a weight just over 2,600 lbs. I would add that the Z4 GT3 has very little in common with its street version counterpart. Winner? There is none, these have nothing to do with the street versions. Racing is just cool.


I think both the Z4 and the new Boxster are fantastic looking, and project a low slung wide road hugging appearance. Both look good with top up or down. The BMW gives you a long front engine bay, almost like an old Jaguar or a Viper. Or maybe even a Z8! Driving the Z4 made me think auto-crossing might be tough because it was hard to see the very leading edge of the car you sit so far back. Not so with the Porsche, I thought the view right down to the pavement was ideal for viewing a tight autocross course. Both test cars had some really sweet looking 19” wheels too. Looking at the Z4 sDrive35is options, made me wonder why BMW has chosen to make the 18” Star Spoke Style 295 standard because the 19s look so much better.

The Z4 sDrive35is I drove had the optional 19” 5 Double Spoke Style 326M wheels, they look a lot like the killer wheels on the new F10 M5.

On to the Boxster, I feel that the proportions just look right. Finally the Porsche Boxster has unique sheet metal and is not forced to share with the 911. Some even think it has elements of the new 918 Spyder. The front-end has wicked cool stacked race inspired headlights as well as large air scoops with radiators behind them. The doors have a sculpted look and actually function to help force air into the large intakes for the motor just in front of the rear wheels force feeding the 9A1 flat six motor.

LED brake lights wrap around the rear quarter panel and some how seamlessly taper into the back and as well as where a speed sensitive spoiler lives. This rear spoiler deploys to decrease lift at highway speeds or by a button on the console. Porsche even has a center light tucked into the bottom edge of the spoiler. The Boxster S’s wheels also look outstanding. I’ll call this category a tie, though confess that styling and looks is totally subjective.

Tie: BMW / Porsche


Despite BMW’s insane power and torque advantage with a 1 Series M engine stuffed under the hood, there is a virtual tie here. Both do 0 – 60 in an identical 4.8. The BMW erases its power advantage with pork. The Z4 weighs over 600 lbs more than the Porsche. I really had no, and I mean no idea the Z4 sDrive35is weighed over 3,500lbs. BMW is the master at dynamically hiding their pork until you get it on a scale. I’ll call this one a tie, but if the Z4 could go on a diet, it’d win. Top speed the Porsche is greater but its really an academic number because I don’t suspect anyone in the U.S. will get close to its top speed on either one.

Tie: BMW / Porsche

Tie: BMW / Porsche


Porsche has electric steering. BMW has electric steering. It appears unfortunate but true that electric steering is here to stay, even from two of the best auto companies in Germany. Electric steering is more efficient and thus yields a marginally better MPG. One just looses the fine nuances in the road, bump steer and it just feels filtered to me. They both loose here.


The Porsche’s top is cloth takes just 9 seconds to stow and for the first time is done solely with at the toggle of a button on the console – finally no latches to jack with. Remarkably with the Porsche, you can stow the top at speeds up to 30mph. What I wanted to do, but managed to suppress on my test drive was start the mechanism of dropping the top then hammer the throttle. With the Z4 you get a folding hardtop that takes a little longer at 20 seconds during which you must remain motionless. This can occasionally be an an issue if a stop light changes on you unexpectedly as happened on my test drive. BMW’s hardtop does give a very elegant look to the car and really seals the cabin from road and noise with the top up.

There is also more than 40% more glass to see out of than previous generation Z4 and way more (scientific term) viewing area than the Porsche. BMW has with the Z4 sDrive35is perhaps their best factory standard exhaust. With the top down, it’s down right intoxicating and I confess was an unexpected treat. The Porsche’s is pretty good but with the top down what you notice more is the high revving motor ripping, not the exhaust. Winner here: Z4.

Winner: BMW


This category was the biggest disappointment to me for the BMW. The Bavarians have always been the car company of more chassis than motor, but not so with this Z4 sDrive35is. It’s not bad until you push the car and I suspect those who buy the Z4 wont drive it on a track or even near the limit. If they don’t, it probably wont be a disappointment to them, but it was to me. Watch the video below and you’ll see I am not alone in my assessment of it.

The BMW to me just seems suited for cruises around town and for the blast up the drive of the country club not the track. Car and Driver put a 2012 Z4 sDrive35is on their Lightning Lap 2012 at Virginia International Raceway. To me, VIR is one of the best racetracks in the country and absolute blast to drive – elevation changes, blind corners, and multiple configurations. It’s like being at a country club or expensive golf course but its for us track addicts. They even have great track food. Anyway here’s Car and Driver’s lap in the 2012 Z4 sDrive35is.

They drove the car to the limit and though my test drive was limited to public roads for both, theirs show what I felt by the seat of the pants in the Z4. I didn’t experience problems with the DCT where it wouldn’t shift while under load like they did but again I didn’t drive like that on public roads either.

The handling category is where the 2013 Boxster S absolutely crushes the BMW. This Porsche just loves to be pushed hard. It has a slightly rear weight balance and it likes to be chucked (pun intended!) into a corner. Maybe a better way of describing it is to come hot into a corner, nail the brakes, scrub off speed, get the car turned in a late apex manner and then you can get on the gas earlier than you think you should.

Here a Z4 would just plow off course going wide in understeer, but the Porsche loads up the wide rears and starts to explode out of the corner on throttle. A little like a 911 would but maybe not as dramatic. In theory with a Porsche it should be slow in fast out, but with the 600 lbs less to turn than the the Z4, it could just scrub off speed fast. Porsche added 1.6 inches to the front track with their new Boxster and 0.7 in the rear and the thing just dares you to push it hard and harder into a corner.

Both German convertibles share an interesting adjustable suspension. Each has three modes. BMW has Comfort/Sport and Sport + Modes and the Porsche has Normal, Sport and Sport Plus. I have our own Hugo Becker trying to figure out if this is the same adjustable shock system on both cars though I am sure both have differing dampening rates. Will report back if we can confirm my suspicion.

Winner: Porsche

Corporate Power:

I won’t rehash what we all know about BMW being an independent company, but this gives BMW the ability to develop unique products with a single focus on providing the “Ultimate Driving Machine.” It leaves BMW very flexible to make what they want, where they want. Where BMW looses on this is perhaps cost savings on shared parts. For Porsche, however, Volkswagen officially completes its takeover of them August 1st. Even before the takeover, Volkswagen had appointed Matthias Müller as Porsche CEO in 2010.

Mr. Müller is a former career VW and Audi executive. Is this a big deal? Maybe, maybe not. But ask yourself, would you rather have a Porsche built at the Leipzig or Stuttgart Porsche factories, or one built at Volkswagen’s Karmann plant in Osnabrück, Germany where the new 2013 Boxster will share the assembly line with VW Golf convertibles? In corporate power, BMW has the edge over Porsche now.

Winner: BMW


Here BMW finally cleans Porsches clock. Though the Z4 sDriver35is I drove didn’t have an iDrive, I’ve used it quite a bit in other BMWs in its most current version. This latest generation of iDrive is a perfect combination of an easy to use interface with a great display. iDrive has a very intuitive dial that gives good tactile feed back, buttons to help you return you if you get lost, pairing Bluetooth, even streaming Bluetooth is all straight forward. The only “dislike” is that you have to USB connect your iPhone to the car to get BMW Apps to work and you still have to jack with the phone to get some of the apps to work so it’s not really plug and forget.

Porsche has come a long long way in the tech world and the influences of the Porsche Panamera are obvious across all their newer designed cars and much welcomed, but Porsche’s still isn’t as easy to use as the BMW iDrive. The little knobs they expect you to use are low and get lost a sea of buttons. Selecting letters even seems backwards. Keep in mind that it wasn’t until 2009 that a Porsche 911 got Bluetooth and you get the idea tech has never been their strong suit. The only thing Porsche has over BMW is the ability to add navigation or other configurable info into dashboard to the right of the tach. Pretty cool. Winner here BMW.

Winner: BMW


I know that BMWBLOG is a BMW-focused website, but in this case I have to call the comparo in favor of the 2013 Boxster S. BMW wins more categories but it does so off of its corporate strengths, not car dynamics or fun factor. Porsche offers a six speed manual, weighs 600 lbs less and offers a real Limited Slip Differential.  Plus I love that Porsche is still manufacturing hi-revving naturally aspirated motors.

Its 3.4 liter flat six is a high revving crisp 315 hp gem all the way to the redline and works well with the Boxster S’ predictable handling at the limits.  I do have to commend BMW for putting a great performance package together for the Z4 with beefier brake discs and calipers, and of course with that awesome engine now used in the 1 Series M Coupe.

Unfortunately, the Z4 is just not really at home when it’s put on the track or pushed hard. The Z4 has way more engine than chassis really, and that’s unusual for BMW. Plus the Z4 even weighs more that the hallowed BMW Z8 which is a full 5 inches longer and is powered by the insane M-Powered V8.

However, one of my colleagues here at BMWBLOG upon learning of my comparo, said “I assume the Boxster will dominate…but I’d still take the BMW.”

Flame Suit on.

[Photos: BMW  and Porsche]