When the pregnancy announcement went out, I could almost hear my friends mocking me in a sing-song chorus: “Pablo’s gonna get a minivan!” I started to panic.
I’ve only owned sports cars and sedans, and our two older children have been comfortably hauled in an E36 M3. But with a rear bench only 50 inches wide, and each child seat more than 20 inches wide, something with third row seating would become an agonizing necessity.
If today’s child seats weren’t so huge I could easily fit five baby butts in the M3’s back seat. Too bad we’re not in the ’70s anymore. It’s a tough world for daddy car enthusiasts today.
Then I had a revelation: Sunshine Kids. Not only do they manufacture high-end child seats, they’ve got the narrowest ones available specifically for my goal—fitting three wide. At only 17 inches wide, Sunshine’s top-of-the line XTSL convertible seat has gotten great reviews, and feature a steel frame and forward- and rear-facing configurations that can safely accommodate kids ranging from a 5-pound newborn to the 80-pound Twinkie lover.
I was set, and after my wife gave me the green light with a “yeah, yeah” along with a roll of the eyes (a “yes” in my book), I found this ’03 Mercedes-Benz S600 with an AMG aero package. Hey, the car is safe, which is most important. It’s also got a twin-turbocharged 5.5-liter V12 pumping out 493 hp and 590 lb-ft of torque, but that’s beside the point. I learned it can easily be bumped to 650 hp. See where I’m heading with this one?
The S600’s performance in stock form is intoxicating. With a mid-12-second quarter-mile at around 114 mph, it feels some 2,000 pounds less when you punch it (maybe not so much while turning). It’s a textbook sleeper with a cabin so quiet you can hear your child’s tummy rumble.
But I’m not very interested in stock Mercedes—not in my garage. That’s where Renntech comes in. Renntech’s founder, Hartmut Feyhl, has 12 years at AMG under his belt, even overseeing the iconic AMG Hammer project built in the ’80s. Numerous Mercedes dealerships across the country sell Renntech goodies because the company’s products don’t void factory warranties.
We upgraded this S600 with Renntech’s Stage 3 package. Rated at a monstrous 650 hp and nearly 800 lb-ft of earth-moving torque, it starts with a recalibration to the engine and transmission ECUs so that it not only makes more power but unlocks the torque limiter on the tranny, bringing it to current AMG 65 specs (it’s the same transmission). The package is also complemented with Renntech’s carbon-fiber intake kit and carbon engine covers, as well as an intercooler upgrade featuring a larger pump and twice the stock intercooling capacity for cooler intake air temps.
For aesthetic touches, the car sports Renntech’s Monolite 9x19 wheels wrapped with General Tire’s new ultra-high performance GMAX AS-03 tires (245/40 front, 275/35 rear). The package provides awesome performance in all four seasons, including light snow, and we didn’t even realize this combination would also be good for a 15-pound weight savings per corner. Coupled with the sporty yet elegant CL-style black grille from 55 Tech Motors, the wheels and tires truly transform the look of this S-Class.
While Mercedes are known to be safe tanks, you’re still at the mercy of a tire puncture and the dangers behind it. To lessen this possibility we installed TyreShield’s tire puncture protection system in all four tires. And yet again we got a performance gain because this allowed us to remove the spare wheel and jack for even more trunk space. Coupled with the wheels and tires, the weight savings total 118 pounds.
After unleashing all that torque with the TCU software update, Renntech’s limited-slip differential was a much-needed upgrade. This unit uses OS Giken internals to power both wheels instead of one, which we’ll test separately in a future Proven installment.
With its new look, diet and performance mods, the car pulls like a freight train. MAF readings now top 65 lb/hr (~650 hp) at wide-open throttle, assuring us Renntech’s power claims aren’t exaggerated. Our GPS-based VBOX PerformanceBox confirms that—at 800-foot elevation on a regularly paved road, no burnout and the traction control on (still too much wheelspin otherwise)—0-60 mph comes in a scant 3.7 seconds, 0-100 mph in 8.5 seconds and the quarter-mile goes by in 12.0 seconds at 119 mph. Don’t forget this is with GT’s all-season tires and a stock exhaust. Of course, we also dyno tested this car (see the following Proven article).
Given the size of the car, performance of this magnitude is flabbergasting. And the fact we can average 22 mpg fully loaded on the highway at 70 mph isn’t too shabby either (no comment on city driving mpg).
Thanks to the Sunshine Kids seats, this Renntech-tuned Benz will play the role of family hauler in the Mazlumian household for years to come. But it’s also got the sports car-thrashing power I crave when I want to outrun the smell of stinky diapers. In fact, I did this recently and surprised the proud driver of a new Corvette Grand Sport. I gave him the ultimate, backhanded “thumbs up” just in time for him to spot the empty baby seats in the back, and then the license plate. He wasn’t pleased.
I’m extremely thankful for the Sunshine Kids find, as that discovery led to everything else here. Contrary to how I thought things would turn out after Rhonda’s surprise announcement, I’m now living the dream, hauling the family in a Renntech Mercedes, something I never thought possible. And I didn’t lose my identity. But, similar to the Vette driver’s reaction, I’m getting ostracized by society.
My friends ask how I could have opted against a minivan. I have nothing against them; I just don’t want one.
But when I say this, I’m looked at as if I’ve broken some modern-day code, or joined a cult or called their wives gorgeous for being big-boned. And it’s recently spawned a recurring nightmare, one that scares me stupid. It involves baby number four, and it’s coming to get me. In a Dodge Caravan. A beige one.
I can’t take that chance—calling the doc tomorrow.
These cars, originally priced at nearly $140K, can be bought for pennies on the dollar today. But while affordable, make sure you get one with a good warranty that covers at least the entire suspension or you could get stuck spending thousands on repairs. Also, having a competent and honest Mercedes mechanic with the Mercedes S.T.A.R. diagnostic computer handy is key to long-term reliability.
Fortunately, I found one in the Kansas City area in European Motorsports, around since the early ’80s, that specializes in Mercedes, BMW, Audi and MINI. They were responsible for installing our spark plugs—a six-hour job because not only does it entail removal of the intercoolers, but there are 24 plugs total. Thankfully, the swap happens only every 100,000 miles.
European Motorsports also installed our Renntech intercooler upgrade kit, which was an additional six-hour job because it involved removing the front clip, installing and wiring the high-flow pump, installing the new heat exchanger with new piping, and finally bleeding out the system multiple times (highly recommended) before reinstalling the front bumper.