Hot rodding and Mother Nature traditionally mix like, well, oil and water.

Carburetors, big engines and smog equipment built for 40-year-old laws are certainly out of step with modern times. Concerns over carbon-dioxide emissions and fuel costs are finally catching our attention . . . and the attention of the hot-rodding community.

The recent Specialty Equipment Market Association (SEMA) show in Las Vegas, Nev., considered the tip of the sword when it comes to the latest trends in aftermarket parts and accessories, was all about technology to convert older vehicles to fuel injection and about swapping old engines for more efficient and technically proficient engines of today. Afraid of technology? Edelbrock will be happy to set you up with a special carburetor that works with E85, the ethanol/gasoline blend that’s just now becoming more widely available. You can also convert your old four-speed manual transmission to an eight-speed (for thrifty highway operation and better acceleration) with a simple bolt-on part thanks to a company called Gear Vendors.

Amongst all the glitter and glitz of the SEMA show, several key trends emerged and the most significant, by far, was that just because gasoline has been around for 100 years doesn’t mean it’s the best or the only fuel we can use. And if today’s top builders have anything to say about it, they’d rather not use gasoline at all.

The trouble is that hot rodding is based on production-car technology, which has, for the most part, been centered on internal combustion engines that use gasoline. And the trouble with that, according to some of the best builders on the continent, is that gasoline is a “junk” fuel that’s better suited to commuter cars and not high-performance cars. Even pump premium, with an octane rating of 91-93 is no match for newer fuels such as E85 and propane with a rating of 105. The higher the octane rating, the more resistant the fuel is to combusting under cylinder pressure without a spark. This uncontrolled burning, referred to as detonation, can destroy an engine in seconds. Indeed the limit to high performance for hot rodders, ironically, is the gasoline used to power their vrehicles. In simple terms, the new fuels allow higher cylinder pressure — compression — for more power without a meltdown.

The claim that E85, propane and even diesel are better for the environment is a pleasant byproduct that will not only sustain the hobby, but ensure social acceptance.

There are few people trying to drive home that point and few who are more passionate about their creations than Johnny Omundson of Obrothers Design, one of a group of companies involved with a 1970 Chevelle nicknamed ProPane. Using a one-off engine block constructed in New Zealand and NASCAR-style Chevrolet cylinder heads, there’s no doubt that this propane-powered machine looks like a hot rod and not some weird enviro-contraption. And according to “JohnnyO” it works like a hot rod, too, even better with more than 1,000 horsepower without the aid of a supercharger or turbocharger(s). Displacement is an amazing 527 cubic inches (about 8.7 liters).

“We want to show what could be done with alternative fuels.

“With 14-to-one compression, it sounds like a top-fueler (drag-race car).

“The only thing is when you first start it up, if you don’t warm the (trunk-mounted) fuel tank the whole top rail will be covered in ice.”

As a summer-only car, this might never be an issue. Hot rodders, take note.

The car was designed by Chip Foose of Foose Design/Overhaulin’ TV-show fame with backing and expertise from detailing company Mothers.

Not far away at SEMA, another 1970 Chevelle lurks, this one with a 1,000-horsepower 6.8-liter Chevrolet “Duramax” diesel. Typically a truck engine, the Duramax’s insertion between the fenders of a Chevelle shows that the engine is not just for pulling boats, although with 2,000 lb.-ft. of torque, that wouldn’t be a problem. The Chevelle even uses the truck-base Allison automatic transmission. Considering an engine swap for your car? This might be one of the most interesting since the powertrain is based on available technology and that outside companies can easily help build a mountain of horsepower to just about any budget.

E85, which is becoming more widely available, is the fuel of choice for entertainer/car guy Jay Leno’s C6RS. The car is based on the current-generation ZO6 model with a 600-horsepower 8.2-liter V8 built by Katech, which also builds engines for General Motors racing programs. Like propane, E85 has a high octane rating, which allows higher compression ratios to build more power. The alcohol component of E85 comes from corn. Although renewal, the fuel does not provide the same kick, volume for volume, over gasoline and requires much more of it to do the same job. Still, the idea of making the most of new fuels is the point and a trend that hot rodders will quickly catch on to. E85 might be the easiest since the same engine can be used with modifications to accept the fuel which is known to be corrosive to some systems normally built for gasoline.