There's no doubt that the right engine can breathe new life into your Mopar, turning your docile, mild mannered daily driver into an animal. And while we know an engine is simply a mechanical set of parts designed to produce torque and power, the comparison of an engine to an animal is not a far stretch. Like an animal, an engine needs the correct respiratory system (induction and heads) to breath properly, as well as a good circulatory system (the oil system) for ultimate survival. Unlike an animal, however, we can choose the lifeblood (oil) that we put in our engine to ensure maximum protection.

If you've followed our annual AMSOIL/Mopar Muscle Engine Challenge, then you know that each year the contest features a different set of rules, a different Mopar engine type, and eight of the country's best Mopar engine builders. In general, we set a basic combination of engine style, displacement, and some years even dictate the cylinder heads and/or the type of camshaft that must be used. Each engine is delivered to the Mopar Nationals, and then transported to Comp Cam's Memphis, Tennessee, research facility where they are placed on the dyno and tested with Rockett Brand 93 octane fuel. Using this fuel ensures the compression of these engines remains at a pump gas friendly level since we know most of our readers' cars are used for street driving.

The rules for this year's challenge are pretty simple and can be found in their entirety on our website, There are some changes to the rules this year, and we're eager to see if our engine builders capitalized on them, but the basic premise of the 2010 contest is a build featuring the Mopar small-block, with RHS's new small-block cylinder heads, and whoever makes the most horsepower per cubic inch is the winner. One thing that won't change this year, however, is the oil we'll be using. Since AMSOIL signed on as the sponsor of our contest, we've been using their 10W40 synthetic motor oil, and this month we'll take the opportunity to show you why.

There are literally hundreds of engine oils on the market today, which makes choosing the proper oil a difficult decision. If you're like us, however, you want the best oil for your Mopar and know that synthetic motor oils use a higher quality base stock, combined with a better additive package, offering more protection than conventional motor oils. As one of the first companies to engineer and test synthetic motor oils, AMSOIL is an industry leader when it comes to understanding what high-performance engines need, and providing an oil that will protect the engine no matter how extreme the conditions. Available in multiple viscosities, we chose their 10W40 for a variety of reasons.

It's been proven on the dyno and at the track that thinner oils will make more power, using less of the engine's power to pump the oil to critical engine parts and reducing friction, windage, and parasitic drag as well. Knowing that our readers comprise a national audience, however, and that engines in different parts of the country will require different viscosity oils for proper operation, we decided to stay away from extremely low viscosity engine oil. Low viscosity oils require special attention to engine clearances, and in our opinion are more appropriate for race engines than the street engines in our contest. Since most of our readers drive their cars in nice weather primarily, we decided to use AMSOIL synthetic motor oil in a well-known and popular 10W40 viscosity. This is a great all-temperature motor oil, offering protection in most of the climates where our readers drive their Mopars.