hi there guys

i have a 05 ex, and from what i understand i should be at least getting 30+ MPG, but from personal calculations taken at when my gas meter reaches the same place right before fill up, after fill up ( miles travelled / (dollars spent / price of gas) )

while i understand, driving conditions, speed, style of driving all take into matter, should i be seeing something significantly higher then 26? i have no performace mods on the car, and i got my oil change just a few weeks ago.

 

well hows your driving foot? if ya stomp it quite a bit or constantly speed that can be normal....

 

City? Hwy? Combined?

 

Your profile says Buffalo. This time of year, short trips suckeven more gas than they do in summer. The cold-start enrichment is stronger because of the low temperatures. And with short trips, there's more %-age of total driving time is spent with a cold engine.

There's a zillion other things that can mess up your mileage. Tire pressures? Dragging brakes? Do you idle the car to warm it up before driving? Snow on the road presents much greater drag to the car.

 

yeah why is that bad?

and i dont lead foot it, and yeah there are a lot of short trips, and this is hiway and local combined

 

Well first off 26 mpg is bad even if you stomp on it. I drive my 99 EX pretty hard and still get 30+ mpg. You might see 26 mpg if you take it to a track and try to keep up with a Ferrari or something. Every time you change speed or brake it uses energy. Your car gets all its energy from gas so naturally stop and go uses more gas then driving long distances. Also engines are more efficient and produce cleaner emissions at higher speeds. On a cold engine the idle speed is about 1500 rpm. I normally wait until I see the temp gauge needle start to move (1.5 - 2 mins) before I head off. Your engine likes it when you warm it up, the tolerances/clearances become tighter. Essentially things fit together like they were designed to. This is why a cold engine sounds so noisy compared to a hot engine. High heat makes for better cleaner combustion and better gas mileage. However too hot can result in pre-detonation/pinging.

There are a lot of people with similar problems as yours in these forums. And in general they all get the same answer.
Check for: (all things that can have an adverse affects on your gas mileage)
old/fowled spark plugs, wrong spark plug gap, distributor cap is cracked or worn, old corroded spark plug wires, dirty air filter, wrong tire pressure, valves need adjusting, wrong engine timing, dirty fuel filter, dirty injectors, dirty fuel rail, dirty throttle body, bad compression (damaged head gasket?), wrong octane gas, dirty oil, bad PCV (positive crank case ventilation valve)

I'm sure there are more, and some of these will have more of an impact then others. Hope this helps.

 

Warming up the engine isn't all thatbad, it just wastes gas. During the whole time it's warming up, it gets exactly ZERO mpg. Average that in with the time driving & you get the idea.

Best for the engine is to start driving (gently) before it's warmed up. I just idle it long enoug to scrape the snow/ice off the windows. Then drive easy until it's warmed up.

The enigne warms up faster by driving. It spends less time in cold-start-enrichment mode. You get less liquid fuel on the cylinder walls to wash down into the crankcase. Only problem is sometimes it's hard to tell the right foot to wait till it warms up...

 

The reason people let there cars warm up in the morning is because the engine is compressed. Everything is tighter because the metal has shrunk. If you put 10w-30 in it. It is going to be like 20-30 w in the morning when its cold. Its harder to circulate it through the motor so it is running a higher oil pressure. When it starts to warm up the motor expands and everything has more space. Its not as tight as it was b4. The fact that your getting 26mpg can be a number of things. Just because one person gets 30mpg+ doesn't mean everyone else does. There are factors like how many miles are on the motor. How it was driven before you got it. How good of condition the motor is in. The climate of where you are. The temperature. Amount of traffic you hit the amount of stop lights you hit. Weither the wind is blowing in the direction your driving or agains you. Theres are such a wide number of factors.

 

First off warming up your engine is not a waste of gas. It helps prevent wear on the engine, which I consider a few table spoons of well spent gas.

This is incorrect.

At an atomic level the atoms are closer when it is cold, but the engine is not "compressed". It would be better to say the metal itself is compressed. The tollerances within the engine are higher i.e. things are farther apart. This is why you adjust your valves on a cold engine and not a hot engine.

This is also wrong.

The exact opposite happens. As the metal heats up the atoms within the metal move farther apart. As a result the metal expands. The clearances in the engine get tigher. This is why a SR-71 leaks jet fuel during take off. The fuel leaks through the metal fuselage because the metal itself is cold. When the SR-71 enters the atmosphere at high mach speeds the friction with the earths atmoshphere creates heat. The metal fuselage expands and everything fits together like it was designed to, and the jet stops leaking fuel. If you don't know what an SR-71 is, google it.

The exact same thing happens in your engine. Bolts expand and fit together more snug. Valves heat up and expand tightening the valve clearances, pistons expand, bearing expand, every component expands. Japanese Engineers desgined your engine based on this concept.

Have you ever had a problem removing a hot oil cap from the valve cover? I have, and not simply because its too hot to touch. The damn thing is jammed in there tight because its hot. When things heat up they expand.

 

the engine is meant to be ran when its warm which means its meant to be ran when it is fully expanded. Which would mean when its cold out the engine is more compressed then it is when its warm. So i am right. When it warms up the motor does expand. The pistons have more room to move in the motor. Thats why when people have problems with your motor. It is the worst when the motor is cold. Because the motor is more compressed then it would be when its warm. When it is warm the sound isn't as bad or it goes away.