What's the highest MPG you can get traveling at least an hour?

I'll start: Dewey, Delaware heading north towards Philly. AC on, some cruise control. Just had my engine air filter replaced (huge difference).

 

Nice. I thought about taking a picture of the last trip i took. I got 34mpg average mph was 69 total trip lenght as 720 miles and it took me 10hours and 35 minutes, ac on the whole time.

I made it home with 32mpg average mph was 73 nearly same milage but i made it in 9 hours a 52 minutes. (I stopped once to sleep this time with about 15-20 minutes of idle time to keep the car cool while i took a cat nap)

Mine car is a 2004 6mt with almost 170,000 miles and a slipping clutch.

 

can i play ?

 

btw OP....

if your average speed is 62mph how did you travel 64 miles in exactly 1 hour ? you reset the trip computer on the highway didnt you, you sly dog you....

 

caught slippin

 

Air filters have nothing to do with MPG.

 

How would resetting it on the highway give him extra miles? You can't reset the time and distance independently..

I have the same issue - my time, average speed and distance traveled never quite match up.

 

How do you figure? He's not talking about the cabin filter.

Clogged filter=additional engine pumping losses=reduced efficiency. This is easily demonstrated. Mind you, it's not going to be 10mpg or anything like that, but an unrestrictive intake tract does help.

Note: not all aftermarket CAIs are helpful, since not all are tuned like the factory intake is.

 

i have an 07 TL-S im bairly getting 300 on a full tank, anyone else got this problem?? this is horrible that's average of 21 mpg's :/

 

I think he meant air filter and not cabin air filter....

clean air filter will give better mileage than a completely clogged one....but this should only change 01.-0.5 mpg and not 2-3 mpg.....

true....

you should be getting more unless you are doing 100% city driving......

 

my car matches up perfectly....imagine you are going 80 mph for 45 minutes....you would have covered 60 miles....in the next 15 minutes you go 50 mph....so you will cover ~13 miles...

so you have covered 73 miles but your average speed will be close to 71-73 mph....i remember solving those average speed questions for my GRE exams...

 

Taken on a road trip.. windows up, a/c on.. mostly flat road.. interstate driving.

Normally, daily driving i get anywhere from 24-26mpg. I think I may have a heavier foot than most, so I'm sure I could improve that number.

 

best ive gotten was 31MPG in my S on the way to syracuse from cleveland. could have gotten 32 but when i leave the tolls.....i LEAVE them

70-73mph , cruise, a/c on, windows closed.

 

The most i ever got was 26 MPG around 75 MPH...

 

Yep, I get the math. I'm just saying any time I check, my AVG Km/h is always 1-2 Km/h lower than simply dividing the distance by time. No idea why.

 

try doing the math when the time is close to the hour....if you check when the time is 0:29 minutes you might find +- 1-2 but when its close to the hour like 2:00 you will find pretty accurate....specially when you are at 10 hours +.....

hope i made sense above....am half asleep LOL

 

The Champ is right, air filter has nothing to do with mpg.... nothing whatsoever lol.

The throttlebody regulates the amount of air going into the engine at anything below full throttle, not the filter. The filter presents no restriction anyway, especially at part throttle. If it did restrict flow, you would get less power and better mpg. But in reality you would open the throttle more to compensate for the added filter restriction which would put you right back where you started.

Pumping losses are greatest with the throttle closed such as idle. Going by the theory presented above, we would get best mpg at full throttle where pumping losses would be lower.

The factory intake is not tuned before the throttlebody, only after. You don't "tune" anything before the TB.

More air in=more power=less mpg.

 

I've gotten >50mpg for an hour. There's a certain stretch of highway around here that allows for this if you're careful and keep it off of cruise control. Average speed can be pretty high while doing it. I have a picture of it taken by my old phone somewhere.

 

I avg 6-7mpg... So I'm out lol

My stock 02 will do 36ish on the highway though.

 

You would probably have the highest city mileage on here if you drove it on the street.

 

good point.

 

I remember you stating your theory before....but i have always experienced the opposite....

imagine you are driving while being careful with the throttle to give you max mpg....a clogged air filter will messes your low end....less air hence giving you more mpg, you cant drive at 30 mph....so to move through the gears you will have to push the pedal harder than you would have to with a clean filter....THIS.....

having to push the pedal more with a clogged filter than with a clean filter is what reduces your gas mileage....

 

my average is 24 mpg and 44 mph over couple hundred hours and 2300 some miles. will post pics.

 

problem is, my max avg mph is 25 thats MAX (city + hwy) i live in miami

 

Pushing the pedal opens and closes a butterfly valve that restricts airflow. That's the only way a gasoline engine is throttled, by restricting airflow. All that matters is how much air the engine is injesting, not how far open the throttle valve is or how far you're pushing the throttle.

The air fuel ratio remains constant so more air= more fuel, less air=less fuel. Whether the restriction comes from the filter or from the throttlebody doesn't matter.

In a carbureted engine, restriction upstream of the carb has the same effect as applying the choke, making the mixture rich and killing gas mileage. Fuel injected cars don't have to worry about this. The filter myth carried over from carbed cars. I posted one time the government study backing me up. The only thing a dirty filter can hurt is power and that's only at full throttle.

It's impossible for restrictions in the inlet tract to hurt low end any different than top end.

 

Interesting...I've always theorized about how that works, but I never thought of the ratio of fuel:air remaining constant. Great way to look at it.

 

I wish mine were that high. After spending hours demoing the system with the engine running plus a very short slow drive to work, I've seen as low as 6mpg.

 

WOW IHC i didnt know the AFR remains constant....i thought you could be running lean or rich...

this is killer good learning....thanks in advance

 

Thanks to the 02 sensors it remains constant. But you're right, this way of thinking comes from the carbureted cars where a plugged air filter really does change the AF and cause bad mileage.

What it really comes down to is the ECU calculates how much air is entering the engine (or it's actually measured on cars with mass airflow meters). It doesn't know if the restriction is from the partially shut throttlebody or the filter or something else, it just sees airflow and adds the appropriate amount of fuel. After it's burned, the 02 sensors check the ECU's AF calculation and adjust as needed. This is one neat thing about it, over time as the fuel pressure may change or injectors get a little plugged or you add a few mods that give more air flow at full throttle, the 02's feedback will make sure the ratio remains the same. You can even see how much the 02 sensors are having to correct the ECU's calculation by the short and long term fuel trim. It's just a number showing how much fuel the ECU is either having to add or subtract from it's original calculation to get that constant AF ratio.

I just wanted to clarify, AF does vary depending on the operating condition. When we go full throttle and especially in vtec, it goes rich. But it follows the same pattern regardless of restrictions.

I hope this makes sense, I'm trying not to fall asleep.

 

no no it does....

this is a lot of info....will go thro the thread all over again to join bits and pieces of info here....Thanks again IHC...

 

34 mpg here.

 

Beat this

 

I think you just won the game by a mile...

 

you shitting me !!!

 

you sure thats a TL and not a prius with TL gauges ???

 

HOW !!!!!!!!!!!!!!!!! .... banging my head in wall

 

RDX injectors ( almost double stock flow). The Mid looks at duty cycle of injectors and they are not being used to their full potential most of the time.

 

so RDX injectors mess up your trip computer eh....MPG and range for instance ?

Reason I ask is coz I was going to install them in my car....pending some AFR readings I get....also how much is the stock and RDX injectors capacities (i thought the RDX were 440cc) correct me if am wrong....

 

Fuel gauge still shows the correct level, but range and MPG is a little off. I can go thru a half tank on a 50 mile drive, but I get about 25 MPG most of the time, mostly freeway.

 

yeah the gauge would be correct as it is directly connected to the tank....

the mpg would be off and hence the range would be off too (fuel left in tank x mpg)....

also if you can answer the above questions it would help a lot....did some searching and cudnt get to the answers....