10/24/2026
🚗 “BUT IT RAN FINE WHEN I PARKED IT!” 😄
We hear this one more often than you might think!
Here lately at United Speedometer and Classics, we’ve had several cars come through the door with almost the exact same story:
“It was running great when I parked it. It only sat for six or seven months. Now it runs terrible!”
And believe it or not, sometimes the car really was perfectly fine when it was parked.
The problem may be what’s been sitting in the gas tank the whole time.
⛽ Let’s talk about today’s fuel.
Gasoline today isn’t quite the same stuff our classic cars grew up drinking. A lot of today’s fuel contains ethanol, and ethanol has a tendency to absorb moisture.
Let that fuel sit long enough—especially in an older steel gas tank—and things can start getting ugly.
You can end up with moisture, corrosion, rust, deposits and deteriorated fuel making their way through the entire fuel system. Now your fuel pump, filter, carburetor or injectors are trying to deal with something they were never very happy about in the first place.
And unfortunately, putting an LS engine or modern fuel injection in your classic doesn’t make you immune.
Actually, now you have electric fuel pumps and precision injectors that REALLY don’t appreciate dirty or contaminated fuel!
Just in the last month, we’ve replaced THREE fuel tanks because of what we found inside them after vehicles had been sitting.
📸 Take a look at these pictures.
This is what can happen when fuel is left sitting for months. It may not look like much from the outside, but inside that tank can be a completely different story.
So if your classic is going to sit for a while, give it a little love before you put it to bed.
Use a good fuel stabilizer and make sure it gets circulated through the system. Consider ethanol-free fuel when it’s available and appropriate for your vehicle. And on vehicles designed to allow it, properly draining the fuel system for long-term storage may be another option.
Keep in mind that even ethanol-free gasoline doesn’t last forever. Fuel still ages and can eventually leave deposits behind.
The important thing is to have a plan before you park the car for months at a time.
A few dollars and a little preparation today can potentially save you from replacing a fuel tank, pump, filters, injectors, carburetor or fuel lines when spring rolls around.
And remember…
Your classic may be taking a six-month vacation.
The gas in the tank isn’t. 😄
Take care of them, drive them when you can, and if you have questions about getting your classic ready for storage—or waking one back up after a long nap—give us a shout.
United Speedometer and Classics
Keeping the classics alive since 1983. 🇺🇸
