As temperatures swung from freezing mornings to mild afternoons this week, Lakeview repair bays filled with familiar complaints: a temperature needle that climbs faster than usual, a radiator fan that seems louder than last winter, and fuel economy that dips after a run of short trips.

At Dock Street Auto, owner Luis Herrera said many of the calls start with the same uncertainty.

“People think of gasoline like it’s only there to move the car,” Herrera said. “But the best mental model is: energy in becomes useful work plus losses. If you don’t know what the losses look like, everything feels mysterious.”

Herrera and other mechanics said the rule can help new drivers connect dashboard behavior to the basic reality of an engine: most of the energy released in combustion does not turn into motion.

The checklist: energy in → (useful work + losses)

On a whiteboard near the shop’s front counter, Herrera sketched his “three-box checklist” for customers waiting on oil changes.

• Energy in: fuel and air burned in the cylinders.
• Useful work: turning the crankshaft to move the car.
• Losses: heat and friction that have to go somewhere.

“If the useful work feels smaller — like the car is sluggish — the losses are often bigger,” Herrera said. “And if the losses pile up, you see it as heat.”

What wastes energy?

Technicians interviewed by the Ledger pointed to several common “loss makers” that show up in everyday driving, especially on short trips.

• Heat from combustion that doesn’t become motion. “That’s the big one,” said Anika Paul, a service adviser at North Shore Motors.
• Friction inside the engine and drivetrain. Bearings, piston rings and gears all resist motion.
• Pumping work. Engines spend energy pulling air in and pushing exhaust out, especially when airflow is restricted.
• Accessory loads. Air conditioning, power steering (on some models), alternators and defrosters add demand.
• Tire and road resistance. Underinflated tires and heavy loads turn more energy into heat.

Paul said drivers often notice the effects indirectly. “You don’t see friction,” she said. “You feel it as extra throttle for the same speed.”

What systems manage the waste?

Once energy turns into heat and friction, the vehicle has to manage it. Mechanics said two systems do most of the work: cooling and lubrication.

Cooling system (heat out):

• Circulates coolant through the engine and radiator.
• Uses a thermostat to regulate when coolant flows to the radiator.
• Relies on airflow and, when needed, radiator fans to carry heat away.

“When you’re moving, the car gets free airflow,” Herrera said. “When you’re stuck in traffic, you’re paying for airflow with the fan.”

Lubrication system (friction down):

• Oil creates a film between moving parts.
• Carries some heat away from internal components.
• Helps prevent wear that can increase drag and heat over time.

“Old oil, low oil, or the wrong viscosity can make everything run hotter and work harder,” Paul said.

What you might notice as a driver

Shops said newer drivers often miss the earliest signals because the car still runs — just less efficiently.

• Overheating gauge behavior: a needle that creeps up at idle, rises on hills, or swings more than it used to.
• Reduced power: sluggish acceleration, especially after extended idling or during hot weather.
• Smells: a sweet odor that can suggest coolant, a hot-oil smell after a hard drive, or a “hot” scent near the grille when stopped.
• Fan noise: a loud fan at stoplights or after parking can indicate the vehicle is working to shed heat.
• Poor fuel economy: more fuel used for the same route, especially with short trips and frequent warm-ups.

“If you’re noticing two or three of those at once, don’t wait for steam,” Herrera said. “That’s the losses getting ahead of the system that’s supposed to manage them.”

A note on old versus modern control

Mechanics said the same energy rule applies across decades, but the way cars react has changed.

Older vehicles, they said, relied more on mechanical control — simpler fan clutches, fixed fuel delivery in some setups, and fewer sensors to adjust for heat.

Modern vehicles, by contrast, lean on computer control. “The ECU is constantly trying to keep heat and efficiency in balance,” Paul said, pointing to strategies that can change how the car behaves: fans that switch on in stages, fueling adjustments under heavy load, and protective responses that can ease power when conditions would otherwise cause damaging heat.

The takeaway, Herrera said, is not to memorize parts but to keep the checklist.

“Energy in becomes motion plus waste,” he said. “If the waste isn’t leaving, it shows up as heat. If it’s leaving too expensively, you’ll see it in fuel.”