There have been a lot of old-car fires lately. I went through the 70s, the 80s and most of the 90s without ever having read much about car fires. Suddenly, they are happening all over the place. Here’s one reason: The ethanol in modern gasoline — about 10 percent in many states — is so corrosive, it eats through either the fuel-pump diaphragm, old rubber fuel lines or a pot metal part, then leaks out on a hot engine … and ka-bloooooie!!!

Leno suggests you actually check out what you put in your favorite ride. Photo by Autoweek

As someone who collects old cars, and keeps them up religiously, I am now replacing fuel-pressure regulators every 12 to 18 months. New cars are equipped with fuel lines that are resistant to ethanol damage, but with older cars, the worst can happen — you’re going down the road, and suddenly your car is on fire.

There’s more. I find that gasoline, which used to last about a year and a half or two years, is pretty much done after a month or so these days. If I run a car from the teens or 20s and fill it up with modern fuel, then it sits for more than two months, I often can’t get it to start.

Ethanol will absorb water from ambient air. In a modern vehicle, with a sealed fuel system, ethanol fuel has a harder time picking up water from the air. But in a vintage car, the water content of fuel can rise, causing corrosion and inhibiting combustion.

Ethanol is a solvent that can loosen the sludge, varnish and dirt that accumulate in a fuel tank. That mixture can clog fuel lines and block carburetor jets. Photo by Autoweek

It gets worse. Ethanol is a solvent that can loosen the sludge, varnish and dirt that accumulate in a fuel tank. That mixture can clog fuel lines and block carburetor jets.

Blame the Renewable Fuel Standard. This government-mandated rule requires certain amounts of ethanol and other biofuels be blended with gasoline and diesel fuel. But when Congress first passed RFS as part of the Energy Policy Act in 2005, our demand for energy was increasing. Today, it’s the opposite. Total demand for fuel has decreased thanks to more-efficient vehicles, more hybrids and increased environmental awareness. The EPA is set to release the 2015 standard in June. Meanwhile, some legislators are pushing to reform or eliminate the Renewable Fuel Standard entirely.

I just don’t see the need for ethanol. I understand the theory — these giant agri-business companies can process corn, add the resulting blend to gasoline and we’ll be using and importing less gasoline. But they say this diversion of the corn supply is negatively affecting food prices, and the ethanol-spiked gas we’re forced to buy is really awful.

The big growers of corn have sold us a bill of goods. Some people are making a lot of money because of ethanol. But as they divert production from food to fuel, food prices inevitably will rise. Now, if you don’t mind paying $10 for a tortilla...

Last week, I went to start up one of my Duesenbergs. When I pulled out of the spot where it had been parked for about a month, I saw a huge pool of gas. I looked at it while it was running and saw gas just pouring out. “OK,
I’ve got to buy another fuel regulator.” I pulled it out and opened it up. The fiber diaphragm was eaten right through. Should manufacturers make diaphragms for old cars out of modern materials like Viton or Teflon? Yes, they should, but not all of them do. Consequently, your chances of a fire remain.

Here’s another problem: When you have vehicles with fuel cells in their gas tanks, ethanol tends to eat the coating out of the fuel cell. If you have an old motorcycle and redo the fuel tank, the first thing you do is seal the tank with some sealant. It’s generally a cream or a gray color, and it looks like you painted the inside of the tank. On a lot of my bikes now, I’ll open the gas tank and I’ll go in with a long set of tweezers. I’m pulling out sheets of this coating. Really, it comes out in 6-inch strips.

The ethanol is just eating it up and clogging the fuel pump because it’ll move around as a sheet of material and block the opening. With cars like my McLaren F1, if I buy a 55-gallon drum of VP racing gas, the fuel cell will last twice as long.

Ethanol is a solvent that can loosen the sludge, varnish and dirt that accumulate in a fuel tank. That mixture can clog fuel lines and block carburetor jets. Photo by Autoweek

It’s time for us as automobile enthusiasts to dig in our heels and start writing to our congressmen and senators about the Renewable Fuel Standard, or we’ll be forced to use even more ethanol. Most people assume, “Oh, that’ll never happen. They’ll never do that.” Remember prohibition? In 1920, all the saloons were closed. It took until 1933 before legal liquor came back.

Most people don’t really look at what goes into their car. Obviously, the days of high-octane gas like Sunoco 260 are long gone. Those of us with older vehicles are the ones who end up paying the price. The car manufacturers don’t care. They don’t mind if your vintage car burns up or breaks down. They want to sell you a new one. It’s hard for enthusiasts. We really have nowhere to go.

So write those letters, but I also suggest you drain and clean your old car’s fuel tank, use a quality fuel-tank sealer that’s impervious to ethanol, replace fuel filters, keep all the screens clear and use a fuel stabilizer (added to a full fuel tank), if your car is to be stored for the winter season.

Oh, and keep a fire extinguisher handy.