6 common tire myths debunked

1. The tire-pressure monitoring system (TPMS) in my new car makes sure my tires are adequately inflated. 

• Our Cars

The truth: TPMS isn't required to issue a warning until pressure is 25 percent below the vehicle manufacturer's recommendation. That's "well below the pressure required for safe driving," according to AAA and "barely adequate to carry the vehicle's maximum load," says the Rubber Manufacturers' Association. TPMS is intended as a last-minute warning before imminent tire failure, not as a monitor to make sure your tires are properly inflated.

Buy a quality tire gauge and set your tire pressure to at least the vehicle manufacturer's recommendation, which is found on the driver's door jamb. I'd rather you set your tires 3 or even 5 psi high rather than 1 low. Tire-pressure gauges can be inaccurate, and tires leak as much as 1 psi per month. Higher pressure improves hydroplaning resistance and, if you're like many folks, you may not bother to check your tires again for six months.

2. When replacing only two tires, the new ones go on the front.

The truth: Rear tires provide stability, and without stability, steering or braking on a wet or even damp surface might cause a spin. If you have new tires up front, they will easily disperse water while the half-worn rears will go surfing: The water will literally lift the worn rear tires off the road. If you're in a slight corner or on a crowned road, the car will spin out so fast you won't be able to say, "Oh, fudge!"

There is no "even if" to this one. Whether you own a front-, rear- or all-wheel-drive car, truck, or SUV, the tires with the most tread go on the rear. Don't believe it? Watch this.

3. A tire is in danger of bursting if pressure exceeds the "max press" number on the sidewall.

The truth: The "max press" number has nothing to do with a tire's burst pressure. The "max press" and "max load" numbers indicate the pressure at which the tire will carry the maximum amount of weight. A new, quality tire will not pop at an even multiple of the "max press." I'm sworn to secrecy about the exact burst pressure, but I wouldn't hesitate to double the "max press" of any new passenger-vehicle tire on a new wheel. But hitting a big pothole at super-high pressures may cause a failure.

4. The "max press" is where the tire offers its maximum cornering grip.

The truth: If you didn't read the previous point, do so now. Many law enforcement officers cling rigidly to the misconception that the "max press" is secret code for maximum at-the-limit traction. It's a coincidence that many low-bidder tires offer increased grip at 40 or more psi. But that's all it is: a coincidence. If I were going to race a stock ex-cop Ford Crown Victoria on street tires on a road-racing circuit, 45 psi front, 35 psi rear wouldn't be a bad place to start. (The tail would be, in Nascar lingo, too loose for safe street driving.)

5. Low-profile tires fitted on large-diameter wheels improve handling.

The truth: The short sidewalls of low-profile tires enhance the tires' response when the driver first turns the steering wheel. That gives the driver the (often false) feeling the tire has tons of grip. But after that initial movement, it's the tread compound—the stickiness of the rubber—that determines how well the tire grips the road. Also, the combination of a large-diameter wheel and low-profile tire is usually heavier than the original equipment. This means the suspension may not be able to keep the tire in touch with the pavement.

6. All tires with the same designation are exactly the same size.

The truth: Think all 225/35R19s (or whatever tire size) are exactly 225 millimeters wide and their sidewalls are exactly 35 percent as tall as the tire is wide? Not exactly. And unlike what's commonly believe, these designations are not about production tolerances.

All the tires of a specific part number or stock keeping unit (SKU) can be can be slightly wider or narrower than the nominal width and their profile can be slightly taller or shorter than the stated percentage. Why? A wider, taller tire puts more rubber on the ground, which is good for a performance tire. A shorter, narrower tire uses less material, thus reducing costs in a business where profit margins almost never break into double digits. So tiremakers might scrimp a bit here and there. It's a bit like how a 2 x 4 is not, in fact, 2 by 4.

SL63 AMG versus SL65 AMG -- Mercedes-Benz Roadsters

Marvel in this beauty!

Check out this 2010 Mercedes-Benz E-Class E350 Coupe. Call us today for a test drive behind a beautiful car!

Mercedes Benz global sales increase 5.5% during January-July 2012

German carmaker Mercedes-Benz has reported 5.5% rise in its sales to 750,251 units during the January to July period when compared to the year ago period.

The carmaker's smart and Maybach brands increased by 5.1% to 813,966 units during the initial seven months of 2012.

Mercedes-Benz Cars Sales and Marketing executive vice president Dr. Joachim Schmidt said despite many model changes and varying market conditions in Southern Europe, for the year to date, the company is on track to set a new sales record in 2012.

"The response to the new A-Class is excellent with well over 40,000 posted orders since it was released for sale," Schmidt said.

"The gradual introduction of additional new models like the CLS Shooting Brake and the GL-Class will give further momentum to our sales."

During the period, Mercedes Benz's sales in Canada reported 10.1% rise, while in Mexico the company's sales reported more than 26% rise when compared to the same period in 2011.

The company sold nearly 147,905 units in the US during the period reporting a 13.8% rise over the year ago period.

Mercedes Benz has reported sales of 97,327 vehicles during July 2012, when compared to 100,391 units sold during the same month in 2011.

Happy Monday fans! Can you tell us the year and model of this Mercedes?

Mercedes-Benz ESP Technology -- Vehicle Electronic Stability Program

2012 Mercedes E 300 BlueTEC Hybrid

It is now clear that gas-electric hybrids, while constantly being refined, are simply never going to gobble up huge slices of any major car market. They are needed, sure, but consumers are already wanting to see what's next, what's even more efficient and more technologically advanced. All the new regular hybrids coming out these days don't really create much excitement since their technology is essentially identical to all of the other parallel hybrids already on sale. So, what is going to keep the hybrid passenger car fires burning brightly and market percentage numbers climbing?

Diesel hybrids. Maybe not in the United States for some length of time, but they are starting to arrive in Europe. PSA Peugeot-Citroën has, at last, started selling Peugeot models with the company's HYbrid4 diesel hybrid system and I've personally enjoyed driving them. Besides the enjoyment factor, the efficiency gains are real.

Now I've have a chance to drive this new Mercedes-Benz E 300 BlueTEC Hybrid, and my excitement is palpable because a big mainstream statement like this from a normally conservative Mercedes-Benz is something this movement has needed. Besides the smart thinking behind committing to this effort in general, Mercedes is launching its very cleanly engineered Modular Hybrid System that can now be plunked into nearly any of its models, much like Toyota-Lexus has been doing for years with its Hybrid Synergy Drive system.

 

A chief challenge to creating a viable parallel diesel hybrid system has been overcoming the sheer costs to the buyer. The adage goes: "expensive diesel + expensive hybrid = expensive diesel hybrid." This may be true on some levels, but we seem to have arrived at a point where the costs of scale are finally helping now that more and more joint ventures contribute to lower pricing.

The other issue has been refinement. Between the potentially rougher on-off nature of the high-compression diesel in a parallel hybrid luxury car alongside the desired start-stop function to help save even more fuel, refining drivetrain feel was simply a qualitative challenge. But from what I can tell based on my long drive of a pre-production E 300 BlueTEC Hybrid on both the European flatlands and over several mountainous passes, Mercedes seems to have the situation mostly licked.

As all manufacturers are realizing, they cannot just leave their stock V6 or V8 in the engine bay of their bigger cars, slap on a parallel hybrid system, charge a mess of money for it and call it good. When car buyers go hybrid, they are volunteering to change their performance expectations of their daily driver, and therefore must be more than willing to change their driving style to get the most out of the shift.

Accordingly, carmakers are currently looking through their vast array of sophisticated four-cylinders to help dramatically bring down the counterproductive weight of a big hybrid car or SUV. In the case of the well-executed E 300 BlueTEC Hybrid, Mercedes turns to its 201-horsepower 2.2-liter CDI, known internally as OM651, a powerplant currently seen in many European 220/230/250 CDI models. Versus the E 250 CDI BlueEFFICIENCY T-Modell (i.e. station wagon) in Europe at 4,070 pounds, the E 300 BlueTEC Hybrid T-Modell adds just over 200 lbs. With that weight you get the lithium-ion battery pack, electronic management system and a compact electric motor capable of 25 hp/184 pound-feet of torque integrated with the 7G-tronic transmission.

I managed to hit 44.4 miles per U.S. gallon and was impressed that the fuel needle barely moved.

You also get a potential range from the 15.6-gallon fuel tank of 870 miles. Over my 120-mile drive, I managed to hit 44.4 miles per U.S. gallon and was impressed that the fuel needle barely moved. One tester in our group managed 54.7 mpg but also admitted to "attracting the ire of many motorists" who were stuck following him. You know the frustrating style of driving I'm talking about. So, no, never in your wildest dreams could you hit 870 miles on a tank, but you could hit over 700 miles while driving fairly normally and pollute impressively little in the process. Not bad something as large and lux as an E-Class wagon.

Regarding E-Class wagons in general, for me, they are nigh unto paradise – even just so far as their relative sexiness and remarkable packaging are concerned. The cargo area is the epitome of easy flexibility with a completely flat floor and no intrusion into the space that might give away that this is any sort of hybrid with a lithium ion battery pack to accommodate. Space back there goes from 24.5 all the way to 68.9 cubic feet.

Acceleration to 62 mph is estimated at 7.8 seconds.

The 12-volt car battery has been moved to the rear of the car while the compact 55-pound lithium ion pack is placed to the right in the engine bay up against the bulkhead, thus putting all the "business" end of this deal up front. Using the equally compact 2.2-liter inline four-cylinder engine has certainly helped make this simplicity possible.

Thanks to the use of the 7G-Tronic Plus transmission, this little four gets some legs to cruise on, fifth gear being the 1:1 and sixth and seventh gears stretching out long. Our revs while cruising fast on no-limit sections of the Autobahn never exceeded 4,000 rpm. The tires are standard Continental ContiSportContact 5 – 245/45 R17 99Y – and they are not so hard that the typical Euro road sound shoots through the chassis to the base of one's neck. Acceleration to 62 mph for our chosen E 300 BlueTEC Hybrid T-Modell is estimated at 7.8 seconds and at 7.5 seconds for the sedan.

This is a big success for diesel hybrids and the entire system has an even larger future in store.

Given that the lithium ion pack is small and good for just 0.8 kWh of energy, the pure EV part of the equation is held to around 1,000 yards max and the integrated eDrive motor is good by itself up to 22 mph. Meanwhile, the eDrive cuts out totally at any speed beyond 100 mph. The 35-cell battery pack is constantly recharging due to engine deceleration and brake energy recuperation, but all of these actions are barely felt thanks to the added NVH work done to separate passengers from the under-hood goings-on. The software research done to smooth out the frequent off-and-back-on moments of the little four-cylinder has reached its apex in the E 300 BlueTEC Hybrid, so much so that it wasn't even a point of conversation all day.

This is a big success for diesel hybrids, and the entire system has an even larger future in store. With any luck (in a sense), things will get so bad with the cost of fuels that more people in the United States will be clamoring for hybrid diesels and stop whining so much about paying a premium for a luxurious and clean Mercedes that runs predominantly via a petite four-cylinder.

With well-designed diesel hybrid systems like this one from Mercedes, the hybrid market share might not level off quite so soon.