Tuning Engine/computer to Maximize City MPG

Most cars have their City MPG lower than their Highway MPG, but the Lincoln MKZ Hybrid lists Fuel economy: 41 city/36 hwy mpg . Is this higher city rating obtained through gear ratios, or computer tuning ?



Is there an after-market technique to maximize City MPG on other cars?

Hybrids typically get better gas mileage in urban driving than in highway driving, and therein lies their advantage.
For the driver who does mostly expressway driving, the “advantage” of a hybrid is…not evident in most cases.

Modern computer-controlled engine management does not really allow the car owner to do much of anything to influence the mpg that his car is capable of, outside of maintaining the car properly, keeping the tires inflated properly, and driving in an economical manner.

This is all the result of the hybrid technology, which captures the energy normally lost to braking is recovered in the batteries and used in the electric motors. You’ll find higher city mpgs with many hybrids.

Prob because it is designed to use electric motor assist much more when in stop and go driving. The electric motor is far more active in city driving while at highway speeds you are almost surely using 100% gasoline engine power and thus mileage goes down. Its the entire premise of the Hybrid tech.

When you drive, pretend that it costs a thousand bucks everytime you use your brakes. Eventually, you will get really good at timing your approach to intersections so that the lights turn green before you get there and you don’t have to stop.
Once you master this art, you will find yourself getting hybrid gas mileage with a conventional car. Your fuel economy will even go “upside down” that is, your urban gas mileage will be higher than your highway gas mileage.
And as a bonus, your brakes will last nearly forever.

I drive my Hyundai Tiburon (5 spd manual) mostly in city traffic. At times, in driving down a hill in 35 or 45 mph traffic, I have shifted into neutral and coasted for up to 1/2 mile when other vehicles are not near. I notice that my rpm,s drop to the 1000 rpm idle rate. It may be my imagination, but my mileage seems to increase if I use this neutral coasting technique 40 +/- times during a tankful of gas. What considerations would support or negate continued use of this coasting technique?

It’s your imagination. You’ll get better mileage if you leave it in gear and coast rather than put into neutral and cost. When you put in neutral, the car is idling which means fuel is still being sent to the injectors when you’re in gear, and you take your foot off the accelerator, then the injectors don’t send fuel to the engine. Also coasting in neutral is illegal in most places.

The subject of coasting like this has been CarTalked to death. The verdict: don’t do it! Wastes gas. Illegal. Dangerous if your car stalls (you lose power brakes and steering). Use the “search” function if you are interested in the past discussions.

Hybrids use the electric engine primarily at low speeds–hence better city mileage. On the highway they use the gasoline motor exclusively and use more gas.

“Is there an after-market technique to maximize City MPG on other cars?”

Yeah: take it easy. Don’t rush up to red lights and stop signs. Avoid hard acceleration.

You’ll get a marginal increase at best…no where NEAR hybrid gas mileage…That would be a 70% increase in gas mileage.