Tesla Roadster Sport driving impression

If you like your head getting snapped back with turbine-like smoothness while removing your dependency on fossil fuels, the new Tesla Roadster Sport is your sports car. This higher horsepower Sport version of the Tesla Roadster, new for 2010, is even quicker. Skipping the '09 model year, the 2010 Roadster model has multiple improvements vs. the first generation including the Sport model. I'll refer to the '08 and '10 as T1 and T2, pun intended.

The Roadster Sport is a $19,500 option over the standard $109,000 Roadster. Adding 40hp to a total of 288hp, the 2,690lb car is very quick. Tesla reports a 0-60mph time of 3.7 seconds which is entirely believable. Considering the power delivery from a dead stop and rear-biased weight distribution, owners can expect this with regularity as traction is excellent.

The "Very Orange" model I drove also had the $9,000 Clear Carbon Fiber Accent Group which made for a very sporty appearance. This paint would be perfectly at home on a Lamborghini. The carbon fiber on the rear spoiler, hood vent and roof cross piece were nice accents complimenting the black finished forged alloy wheels.

The drive selection lever from the T1 is has been replaced with lighted buttons; park, reverse, neutral, and drive. At low speed the first thing noticed is the silent and smooth drive-off, much like a golf-cart. Turning the steering wheel at low speed and you immediately notice the unassisted effort. A larger steering wheel would probably work if the extra leverage could be felt.

Eerily quiet at first, punch the accelerator (no longer the gas pedal!) the response is immediate. This is truly a point-and-shoot type of car. There is no build-up of acceleration, no downshifting, no lag, no hesitation, nothing. It's like always being in 1st gear. The 3.7 second 0-60mph is so easy and even turning off the traction control, I couldn't get the aggressive Yokohama A048s to break loose on dry pavement. Believe me, I tried. A brake torque doesn't do anything either.

Like the Lotus, the steering wheel wiggles over bumps but smooths out at speed unlike my impression of the Lotus. However, around triple digits it loosens up again. But this car isn't about high speed cruising. The motor whine is noticeable and a little loud but what I found more disturbing was the excessive wind noise around the A-pillars and removable soft-top. I'm told the hardtop reduces the noise noticeably.

Having seen a Tesla T1 crack off a 12.9 1/4 mile run, and multiple tests put the car in the high 12second range at 103-105mph, the T2 Sport is quicker but probably won't pick up any mph. I say this because acceleration noticeably falls off after 75mph due to the nature of the engine and powerband. An owner has ran a 12.643 ET, but at only 102.89mph. 

To put it in perspective, a Ford "Terminator" Cobra with bolt-on modifications and stock pulley caught up from a 2 car length deficit at low speed and streamrolled past me once it hit 3rd gear. This car rocks up to legal speeds though. To be honest, that is all anyone really needs on public roads.

The ride is very compliant and quite comfortable. The body roll is minimal and despite the weight distribution, this one was tuned to predictable understeer. The Sport model includes 10 level shock adjustments, 3 position anti-roll bars and a remote shock fluid reservoir. It has very high cornering limits, the non-Sport model recording .90 and .92 on the skidpad so despite nice seats, better side bolstering is needed.

Braking is quite good and I would be curious how the Sport model compares in an instrumented test with it's softer, more aggressive tires. The brake lights activate automatically because the car will decelerate at a rate to activate energy regeneration when off the throttle. Apply the brake pedal for a quicker stop or modulate the accelerator. Again, like driving a car that is permanently in a lower gear.

Getting in, despite a .5" narrower sill, cover, now carbon fiber, is still quite difficult for a 6-footer. Literally climbing out is hardly easier. A side-by-side comparison would be needed with the Lotus Elise, but I seem to remember it being a little easier. Remember, the Tesla has major structural revisions to cope with the battery weight. You can read my review of the Lotus Elise here, but keep in mind, it's based on a very small car. My left calf rested against a support structure on the left side and the lower center console on the right.

When my Pretty Navigator, who is used to large sedans, first saw the car she asked, "Where is the rest of it?" And then during the walk-around, "Oh Honey, it's so cute!". But that isn't so bad because when you really like your passenger, sitting shoulder and hands on thighs is kinda nice.

The view for the ventilation controls were partially obstructed by the dashboard ledge under the radio. One advantage though is the immediate response of the heater - you don't have to wait for engine coolant to warm up since an electric heater starts producing heat immediately.

Having driven about 60 miles with a lot of full-throttle bursts and 75mph cruising, despite the limitations of a very small car design with weight concessions such as soundproofing and wind noise, Tesla has done an admirable job modifying an existing platform and developing a powertrain that is undoubtedly functional, fun and reliable for everyday transportation. As of the writing of this article, Tesla Co-founder Elon Musk's '08 Roadster has over 13,000 miles on it.

Keeping mind no gas station fill-ups, no oil changes, no engine warm-up, minimal maintenance (no spark plugs, belts, air filter, pcv valve, etc. etc), electric vehicles are here to stay. This one is groundbreaking and may be the most fun EV for a long time.

Stay tuned for a future article on Tesla and the improvements made for the 2010 model year.

Instrumented tests with spec sheets: Car & Driver and Road & Track

Sound Off! Lexus LF-A vs. Mustang GT

The super high-tech, incredibly fast and expensive ($375,000) Lexus LF-A actually has something in common with the $30,000 '10 Ford Mustang GT. Believe me, they don't share any common components and they are not even remotely related in any way. But they do share one common trait that is rather unique. They both have methods of directly transmitting the sound of the engine into the passenger compartment.

The new 560hp Lexus LF-A, with it's 9000rpm V-10 engine has sound tubes that transmit the engine sounds into two locations in the passenger compartment. As reported in the December '09 Road & Track, the sound comes in above and below the dashboard. The 2010 Mustang GT also has a "sound induction tube" as reported in Car & Driver, February 2009.

To be perfectly honest, it's an ugly addition to the engine compartment on the Mustang. Looking at the photo here, it unfortunately looks like an afterthought and creates clutter. This engine compartment looks better.

Is this a sign of performance cars being so refined that sound effects are needed to engage the driver? As if the car is so quiet that the enthusiast driver receives so little audio feedback the factory deems it necessary to "pipe it in". What happens when the owner installs a less restrictive "cold air intake"? That is a common upgrade that not only can increase horsepower, but also the audible sound level of the engine as well. Will these "CAI's" still allow for the "sound injection" as well?

Is it another foreshadowing of upcoming sound regulation? Electric cars are naturally very silent and so are hybrids when under full electric power. Is there anticipation of internal combustion engines having even stricter sound requirements? That doesn't bode well for diesels, does it?

A question I always ask is how much R&D and resulting cost did it take? And for these cars, was it really necessary? Is there an after-thought to discourage modifications to the cars?

If that much R&D goes into the sound tube design, shouldn't it be driver selectable? Many want the speed, but what about their music? Gotta have the tunes! Others may want to impress those outside of the car. with the sound. If there are passengers, they are already impressed, right? Hopefully by both you and your car.

Unless exterior sound regulations get so outrageous, I predict the sound tube fad may become an adjustable "feature" in high-end cars and simply fade away in the rest. Just like the digital dashboard. Which, by the way, the Lexus LF-A also has but luckily in the shape of a traditional speedometer and tachometer. The reason? Lexus states the engine revs too fast for an analog gauge to keep up.

So do you want two volume control dials plus the one under your right foot?
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Got a question about cars you would like answered? Want to know about performance, racing, modifying, shopping, makes, models, events, etc? Ask me here: AskRobAboutCars@gmail.com and I'll do my best to answer your question and publish it here on Examiner.com!

How fast? And is it stock? Bone Stock defined

How quick and is it bone stock? That is the question among fans and owners of various cars with lots of debate about who is faster. Top speed is easily measured by magazines and meaningless in terms of acceleration. Zero to 60mph sounds good but doesn't tell the whole story. The 60-130mph timing is growing in popularity but many don't have the means to measure it. My article about that here. It all comes back the the 1/4 mile drag race.

The trap speed is the real indicator of which car is quicker once rolling and takes out the factor of a bad start (launch). In this age of the internet, claims and scanned timeslips can be seen across the country causing instant rivalries and debates. But the question remains, is it stock or modified? Is it just as it was off the showroom floor or has it been secretly enhanced?

The following examples are trap speeds that push the envelope of believability and all of them have the these factors in common: Great driving, proper vehicle preparation and cold, crisp air for maximum horsepower output. Examples such as: Corvette ZR1: 132mph, Dodge Viper ACR: 130mph, Corvette Z-06: 129mph, Dodge Viper 4th gen: 129mph, 03/04 Ford "Terminator" Cobra: 115mph, SRT-8 Charger/300C: 111mph, 05/06 Pontiac GTO: 110mph, 98-02 Camaro/Trans-Am: 110mph, Dodge Challenger R/T: 108mph and many more. Funny thing in the realm of "who is faster debates" is that in most cases, subtract 1mph from many of those and there are suddenly multiple examples.

A "bone stock" vehicle must be as if it rolled off the showroom floor. There are many ways to "cheat" but no performance modifications are allowed. In another article I'll list some drag racing tips for those looking to maximize the performance from their street car.

The rules of "bone stock" are as follows: The original or similar paper air intake filter must be in place. The stock shifting mechanism cannot be substituted for a short-throw shifter, the tires must not be designed for drag racing (drag radials). The vehicle cannot have weight reduction by removing parts. The spare tire is debatable but that weight difference is easily made up with differences in driver weights so I say it's okay. The exhaust as it came from the showroom floor must remain as well.

When magazines test cars, they may be criticized for not representing the "real world". If you take into consideration they don't do any type of weight reduction, a full tank of gas usuallyy, no powershifting, no "drag prep" techniques, they start to look pretty realistic. Another factor is automated clutch cars (single and dual) and fully automatics (torque converter) will have minimal variance. Finally, taking into account the magazines sometimes have fairly fast times because they do not use a dragstrip where the last 60 feet is used as an average for the trap speed, the results are spot-on for probably 90% of the bell curve. Variance due to condtions alone can be huge. A 50 degree swing in outdoor temperatures can translate to about 5mph.

Really the meaning of "bone stock" is pretty basic and the trap speeds listed are in the extreme minority and a couple are no doubt questionable. Others are verified and it's really a simple rule: The same equipment as when the car rolled off the showroom floor, from the factory, no more, no less.

Design flaw in the new McLaren MP4-12C?

There is a disturbing trend in the automotive world of eliminating the limited slip differential (LSD). Manufacturers are promoting alternatives with fancy names, but none of them do what an LSD can do and this can be an issue. If you're spinning, you're not accelerating. This can be a big, big problem on the street and on the track for reasons I'll explain.

According to Road & Track Magazine, Nov. 2009 issue, the upcoming McLaren MP4-12C doesn't have one! This car has every ingredient to make it one of the greatest sports cars on the road except for the potential penalty of lacking an LSD. This is could be a major compromise from a company that is renowned worldwide for it's engineering expertise and racing pedigree. Multiple championships in Formula 1 and at the worlds fastest production car for 7 years are their best known accomplishments to the public.

The MP4-12C is their first entirely designed in-house street car that will compete head-to-head against the upcoming Ferrari 458 Italia and F430, Porsche GT2, the Lexus LFA and the Lamborghini LP560. Pinnacles in modern sports car design with lightweight materials and horsepower levels in the mid-500 range for extreme performance and race bred technology for the street and for the track. Ferrari in particular emphasizes their E-diff for 32% better longitudinal acceleration vs. the F430 and 1.25 second improvement in lap times at their Fiorano track. Read more about it here. The Porsche is a rear-engine design and the Lamborghini is all-wheel drive, both of which aid traction.

Other greats like various BMWs and Porsches also have this "deficiency" as well, but not their flagship or higher performance models. The BMW 335i series vs. the M3 is an example of the more sport orient ed model having a limited slip differential. Due to owner feedback (complaints), the Dodge and Chrysler SRT-8 models finally received LSDs in their 4th model year. One could surmise several specific makes and models always have LSDs. Corvettes come to mind. How about Ferraris? It's a safe assumption, one would think.

With an "open" differential, both wheels apply engine power to the ground and even can lay down twin black strips of rubber when there is a loss of adhesion or overpowering the tires. However, when one becomes "unloaded" due to less traction and starts to spin, the power isn't transferred to the other wheel which means the rate of acceleration doesn't increase. This causes headaches on the street, the racetrack and the dragstrip.

Most annoyingly daily driving can be compromised. Uneven surfaces encountered pulling out of a parking lot or driveway onto a road when the rear tire (or front tires for front wheel drive vehicles) slips and the manufacturer promoted traction control kicks in. Begin accelerating and if aggressively programmed, the engine power could be reduced besides just the rear brake being applied. A real pain in the ass. A little extra brake wear over time and now you're maintaining your speed or slowing down when you should be accelerating. Try it when a vehicle is headed your way and you "thought" you had enough time... That is why many drive with Traction Control partially off. I'll control my throttle, thank you very much.

How about in rain and snow? Drive over or start on a slippery patch and you just sit and spin, the wheel with traction never getting the available power transferred. Apply more gas and you spin faster. Great. At the dragstrip it's the same thing. Get "out of the groove" with one tire and the other doesn't pick up the slack. For those that run higher traction tires such as drag radials at the dragstrip, the uneven distribution of the power from one side vs. the other can break a rear differential or half-shaft at some point.

Where all these exotic cars are meant to be is on the race track and the potential oversight of the McLaren means in tighter turns, the inside wheel can spin and power isn't then applied to the outside wheel of the turn, meaning a slower corner exit. Spinning is neither winning nor accelerating.

There has to be a good reason why the McLaren doesn't have an LSD so I contacted them with that question. The MP4-12C has multiple systems that they call the Proactive Chassis Control system that McLaren feels eliminates the need for the LSD.

The system consists of adjustable roll control for precise body lean control during high lateral acceleration cornering and it decouples for a better ride when in a straight line. The shocks are interconnected via hydraulics and adjust depending upon conditions and driver preferences. Finally it has a system called Brake Steer which brakes the inside rear wheel when braking into a corner and if spinning when accelerating out of a turn. Obviously brake steer is controlled via electronics and McLaren feels this eliminates the need for the more mechanically complex and heavier LSD. In other words, optimize chassis control and steering and the power delivery takes care of itself.

Granted there are some innovative weight savings with the MP4-12C such as the 175lb carbon MonoCell tub. Interestingly, aluminum brake hubs are used but not carbon ceramic rotors. Also the body panels are not carbon fiber either. Couldn't the weight of the LSD be offset in more traditional areas? I wonder if an LSD would actually be larger, compromising the design with the mid-engine and transmission placement. Perhaps it would have meant additional width, length or even height to the components, raising the center of gravity?

The drawback of a limited slip differential, besides extra cost, complexity or weight (as I roll my eyes) is potential snap oversteer which means when then the wheel with traction "hooks up" suddenly from excess power, it could cause the car to fishtail. That is something you could catch on Youtube. The "open" differential is quite predictable since the power isn't being transferred to the other side. The other disadvantage, and it's quite minor, according to the SRT Engineers the constant transfer of power can cause a ever-so-slightly decrease in acceleration. The benefits far outweigh the costs.

Adding an LSD is a common upgrade among owners of many performance-oriented cars via aftermarket parts. Can it be done with a rear transaxle, dual clutch transmission in a mid-engine car? Doubtful. There are reports of a planned hardtop convertible version of the MP4-12C that would be a first for a mid-engine car. Could this be a business decision to keep the components lower in the chassis, forgo the LSD and accommodate the folding top design? Also a higher performance is supposedly planned and perhaps this model will be "properly" equipped.

The reason many manufacturers leave out a limited slip differential is because of cost savings, pure and simple. Less mechanical parts means less cost. If it was a size and packaging issue that meant raising the center of gravity, extending the wheelbase, or something else radical, will it mean the McLaren, while wildly fast and capable will still be left behind by the competition?

2/8/2017 Edit:  Car and Driver published an article comparing an electronic torque vectoring differential vs. a standard limited slip differential in the Lexus RC-F in October 2015. They didn't bother with the obviously slower brake torque vectoring open differential. The e-diff car was quicker around the track and higher skidpad results. www.caranddriver.com/features/whats-the-diff-we-put-torque-vectoring-to-the-test-feature

6/1/2019 Edit: Being that the cars are fair weather driven, with rear weight bias, the open differential seems to work for McLaren with the selective brake bias (braking one rear wheel) used for quicker turn-in. This may cause excessive wear on the brake pads, but that isn't the concern. Meanwhile the E-diff continues to be the preferred equipment among other manufacturers.

Having driven over 150,000 miles in a '06 Charger SRT-8 6.1 and a BMW 335d, both with 425lb ft. torque (when stock), I can attest that open differentials suck. That's why owners screamed for an LSD and Dodge later added it as standard equipment.
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Got a question about cars you would like answered? Want to know about performance, racing, modifying, shopping, makes, models, events, etc? Ask me here: AskRobAboutCars@gmail.com and I'll do my best to answer your question and publish it here on Examiner.com!