question: Why are engine retarder bakes prohibited within most city limits?
comment: That's...what? Engine braking is generally prohibited, but in that case it's a diesel-thing (although GDI engines should be able to do it); you allow the engine to compress air inside the cylinders (which converts the vehicle's kinetic energy into work being done on the air in the cylinders) and then you open the exhaust valves very early, which removes the pressure (and which reclaims no energy as work, meaning all that compression is lost, helping to slow the vehicle). You also inject no fuel during this process. It's often banned because diesel engines operate at very high pressures, thus the sound generated from this high pressure air escaping the cylinders is [quite loud.]( URL_0 )
passages: Early internal combustion engines were quite successful running on gaseous and light petroleum fuels. However, due to the dangerous nature of petroleum and light petroleum fuel, legal restrictions were placed on their transportation and storage. 
   The tax is levied against manufacturers of new "cars" that fail to meet the minimum fuel economy level of 22.5 miles per gallon. The tax does not apply to minivans, sport utility vehicles, or pick-up trucks, as these made up a small portion of the US fleet when the tax was established in 1978. Manufacturers pay a level of tax based upon the average fuel economy for each particular vehicle produced, ranging from $1,000 for vehicles achieving at least 21.5 but less than 22.5 MPG, to $7,000 for each vehicle achieving less than 12.5 MPG. Vehicles that achieve a minimum average fuel economy of 22.5 MPG are not subject to the gas guzzler tax.
   Prior to Clean Air Act of 1970, a majority of muscle cars came optioned with high-compression engines (some engines were as high as 11:1), which required high-octane fuel. Prior to the oil embargo, 100-octane fuel was common. However, following the passage of the Clean Air Act of 1970, octane ratings were lowered to 91 (due in part to the removal of lead as a valve lubricant). Manufacturers were forced to reduce the compression ratio of engines, resulting in reduced performance. Simultaneously, efforts to combat air pollution focused Detroit's attention on emissions control rather than increased power outputs.
  
  Section::::History.:1980s–1990s: Performance revival.
   On December 21, 2004, the Air District's Board of Directors adopted Resolution 2004-16 to increase the surcharge on vehicles registered within the District boundaries from $4.00 to $6.00 per vehicle. The Department of Motor Vehicles began to collect the increased surcharge in May 2005. The revenues from the additional $2.00 surcharge are deposited in the District’s Mobile Source Incentive Fund.
  
  Section::::BAAQMD Carl Moyer program history.
  
  1998 – Carl Moyer Program is established. The program receives $25 million in funding. The Bay Area Air Quality Management District begins funding engine upgrades in the San Francisco Bay Area.
   Another daily hazard, the Skonk Works, was almost as lethal. Scores have been done in by the fumes of the concentrated "skonk" oil which is brewed and barreled at the factory by its owner and “inside man”, Big Barnsmell; and his cousin, "outside man" Barney Barnsmell (see also Skunk Works). 
   Laws exist in all states and territories that limit modifications done to vehicles and prohibit having nitrous oxide hooked up to, or even present inside a car. In most states and territories P-Plater (Provisional Drivers) are not allowed to drive any vehicle with more than six cylinders as well as turbo. In most states further laws impose strong penalties for street racing such as confiscating/impounding the vehicle and loss of license.
   This provision is an "objective emission" control. It can define the method of vehicle operation that is used to define the maximum permitted sound level. It can have a curfew. Some states exempt motor vehicle racing events from noise disturbance litigation or prosecution. Arizona (Section 28-955.03) exempts racing motorcycles from maximum sound levels and muffler requirements. Illinois {Section 35.903} had detailed regulations on racing vehicles It required a 14 dB reduction in sound output, limited sound output at half mater to 115 dB(A), and no more than 105 dB(A) at 50 feet.
   An example of a recognised independent testing program to "evaluate aftermarket retrofit devices which claim to improve automotive fuel economy and/or reduce exhaust emissions" is that run by the US Environmental Protection Agency (EPA) identified by test program authorities 42 USC 7525 and 49 USC 32918, and formerly known as the "511 Program".
   BULLET::::- Modifying the engine to run an alternative fuel. These include natural gas conversion of gasoline-powered cars and Vegetable oil conversion of diesel cars. Cars with Diesel engines can be converted reasonably cheaply and easily to run on 100% vegetable oil. Vegetable oil is often cheaper and cleaner than petrodiesel, but local laws often levy harsh fines to users who fail to pay fuel taxes when acquiring their fuel outside regular distribution channels. Liquid nitrogen, Hydrogen fuel conversions and Ethanol conversions are other alternative fuel conversions that can be done with internal combustion engines. The first two will eliminate all vehicle emissions, while the third one will only slightly decrease emissions.
   In jurisdictions such as California, with strict, arbitrary smog rules, it may not be possible to register a late-model vehicle with an engine swap, even if it can be proven to produce less pollution than the original engine (owing to "visual inspection" rules).
   The Red Flag Law was repealed in 1896, by which time the internal combustion engine was well into its infancy.
  
  Section::::Red flag laws in the United States.
   This type of retarder is known as compression release engine brake or "Jake brake". A disadvantage of this system is that it becomes very noisy in operation, particularly if the exhaust muffler is faulty; its use is, therefore, banned in some locales.
  
  Section::::Engine brake.:Exhaust brake.
   Many countries or municipalities have legal requirements which govern vehicle modifications. For example, all vehicles in Victoria, Australia, must conform to construction standards to ensure vehicle safety. There are also restrictions for P Plate drivers which can prevent young drivers from driving modified vehicles.
  
  Many developed countries have smog regulations, which generally forbid any modifications to engines or related components unless the modifications themselves are certified, like production car models. Such modifications, even if they do not actually result in increased emissions, prevent legal use on public roads.
  
  Section::::Sanctioning organizations.
   BULLET::::- AAA Michigan sponsors Detroit Clean Sweep, an ongoing program involving club employees who help promote a cleaner environment through volunteer activities such as collecting litter. In addition, the club's Freeway Courtesy Patrol vans cruise local roadways to assist motorists and help reduce congestion.
   To meet these regulations, manufacturers have adopted a variety of improvements, including increased use of four-stroke engines, the use of direct injection for two-strokes, and the use of catalytic converters and other pollution-curbing measures that overall have reduced emissions by approximately 75% compared to pre-regulation models.
  
  In some areas, such as Lake Tahoe, outboard motors and PWCs are permitted if they meet the 2006 EPA or California Air Resources Board (CARB) 2001 regulations. Some pre-2006 model year PWCs meet this EPA standard, including all four-stroke makes and models and all two-stroke cycle direct-injection (non-carbureted) models. 
   The combined fleet fuel economy for an auto manufacturer of cars and trucks with a GVWR of 10,000 lbs or less will have to average 35.5 miles per gallon (mpg). The average for its cars will have to be 42 mpg, and for its trucks will be 26 mpg by 2016, all based upon CAFE Standards. If the average fuel economy of a manufacturer's annual fleet of vehicle production falls below the defined standard, the manufacturer must pay a penalty, currently $5.50 USD per 0.1 mpg under the standard, multiplied by the manufacturer's total production for the U.S. domestic market. This is in addition to any gas guzzler tax, if applicable.
   The United States Environmental Protection Agency (EPA) has taken numerous enforcement actions against car makers and other companies that have used or installed defeat devices, whether deliberately, or through error or negligence. Aftermarket parts or software, such as modified exhausts or chip tuning products and services, are considered defeat devices if they inhibit or bypass a vehicle's emissions controls.
  
  Section::::Timeline.
  
  Section::::Timeline.:1970s.
   The following vehicles were included in this class-action suit settlement:
  
  BULLET::::- Mercury Grand Marquis, 1996–2001
  
  BULLET::::- Lincoln Town Car, 1996–2001
  
  BULLET::::- Ford Crown Victoria, 1996–2001
  
  BULLET::::- Mercury Cougar, 1996–1997
  
  BULLET::::- Ford Thunderbird, 1996–1997
  
  BULLET::::- Ford Mustang, June 24, 1997 – 2001 (some vehicles)
  
  BULLET::::- Ford Explorer, early 2002
  
  Section::::Spark plug issues.
   Section::::Records.:Drag racing.
  
  American Motors was not actively involved in auto racing during the early 1960s as not to glamorize corporate sponsorship of activities that promote dangerous speeds and driving. It continued to support the 1957 Automobile Manufacturers Association (AMA) prohibition on automobile racing. The automaker ran national advertisements: "Why don't we enter high-performance Rambler V-8s in racing? Because the only race Rambler cares about is the human race."
   Free-flowing exhaust systems may maximize peak horsepower by reducing or eliminating back pressure; this is typically accomplished by making the path as straight as possible, using a consistent diameter throughout the system and eliminating obstacles such as catalytic converters and pre-catalytic converters or by replacing the muffler with a less restrictive (and usually louder) one. Despite the potential for increased performance by eliminating catalytic converters and other emissions control hardware, doing so will often render the vehicle illegal for street use in many jurisdictions. Other aftermarket modifications that bypass the catalytic converters and/or mufflers, such as electric or cable activated exhaust cutouts—which open and reroute the exhaust flow to bypass restrictions in the system—can similarly increase performance, though would likely be illegal in areas where tampering with emissions devices is prohibited, particularly when placed in front of the catalytic converters.
   At present, final drive ratios higher than 3.20 (3.2 engine rotations to one rear axle rotation) are prohibited, in an effort to limit top speed potential, thus reducing the perceived level of danger.
  
  Section::::History.
  
  In 1957, NHRA banned nitro in all categories; the American Hot Rod Association (AHRA) still allowed it, and Fuel Dragsters (FD), Hot Roadsters (HR), and Fuel Coupés (FC): this led to Fuel Altereds (AA/FAs), Factory Experimentals (A/FXs), and (ultimately) Funny Cars (TF/FCs).
   BULLET::::- Maine—annually, only in Cumberland County. Also required by ordnance in Sanford, Maine but unenforced as many go to other towns to get inspected car and police cannot arrest or decline registration or inspection of Sanford car as its not mentioned in state law .
  
  BULLET::::- Maryland—biennially, required in 13 (out of 23) counties and the independent city of Baltimore. The most recent two model years of vehicles are exempt from emissions testing.
   BULLET::::- The advanced clean car rules program was made to reduce tail pipe emissions. The Air Resources Board approved the program to control emissions for newer models from the year 2017 to 2025. Some of their goals by 2025 are to have more environmentally superior cars to be available in different models and different types of cars. New automobiles will emit 34 percent fewer global warming gases and 75 percent fewer smog-forming emissions. And if fully implemented consumers can save an average of $6,000 over the life of the car.
   Although Ford's Drag Pack option with a special oil cooler was never formally offered on the Boss 302, it was often included with the 4.30:1 rear axle ratio. This coveted option is recognizable when the hood is opened to reveal Ford's vertically mounted oil cooler in front of the radiator. Ford also had an option for Boss 302's and 429's for deluxe interior rather than standard interior 
  
  Section::::First generation (1969–1970).:Trans-Am racing.
   BULLET::::- Refueling may be done at home, but filling the tanks to full pressure would require compressors for 250-300 bars, which are not normally available for home standard utilization, considering the danger inherent at these pressure levels. As with gasoline, service stations would have to install the necessary air facilities if such cars became sufficiently popular to warrant it.
  
  BULLET::::- Compressed air engines reduce the cost of vehicle production, because there is no need to build a cooling system, spark plugs, starter motor, or mufflers.
  