I hate cars

Nope. The throttlebody determines how well it breathes everywhere except WOT. By your theory you would get worse mileage at lower throttle with the butterfly blocking airflow.

Freeing up the exhaust side will give mpg gains but not the intake side.

Only on carbureted cars will a dirty air filter affect mileage.

JWTL04

you may be right i have never truelly tested this theory since everytime i have upgraded the Intake i have done an exhaust upgrade at the same time. It would be interesting to see what my mpg will be when i get my new exhaust system on. unfortunately i wont be able to get the new exhaust on in time for my beach trip.

HydeCiel

I am going on a long road trip on Wednesday night. I'll be driving down to Georgia from Maryland for a convention, all highway driving. I know if I stay around 60-70MPH I will get an average of about 32MPG.

I will test this out.

I will use cruise control and try to stay at a constant MPH per tank fill up. Also, trying different constant speeds to see what is the best for cruising.

I will report back with my findings for when I drive to and from.

Cheers,
HydeCiel

JWTL04

On that note does anyone make a bigger throttle body for the TL?

because if so then would adding a bigger throttle body and spacer increase fuel mileage?

JWTL04

I find it easier to get better fuel mileage not using cruise control. Has anyone else tried not using cruise control. I know it helps to keep an overall speed but i find that sometimes it kicks in and revs up the engine when i could have coasted a little more. Plus it allows me to better control the throttle since cruise control is designed to keep the car at a constant speed. Most operate in a 6 mph range. So if you set the car to 65 then cruise will keep it between 62-68 mph before making the car accelerate or deaccelerate. Thus making the car use more gas to keep a constant speed. Just a thought.

HydeCiel

That is a fair and good point. I will keep that in mind. I will be doing a lot of driving, so I have lots of chances to test these things out. I will try without the cruise control for one tanks worth of gas at the very least.

Thanks for the info!
Hyde

I hate cars

In theory this would work but in reality it won't . The AF ratio is kept constant so more air=more fuel.

Exhaust is different. The engine has to pump out the exhaust gas and this takes power. It can also cause some of the exhaust to be left behind in the cylinder diluting the fresh charge and losing power. Reducing backpressure will give you both power and mpg since the engine won't have to pump as hard to get the exhaust out to the tailpipe.

What it comes down to is the engine is throttled by restricting the intake. Exhaust is always wide open.

JackSampson

iTrader: (2)

Our cars suck for fuel economy if you drive alot in the city.

SmileyOr

I have yet to put more than 14.5 gallons into my tank when the MID fuel light comes on. An I have seen 350+ miles on the odometer.

myblack04tl

After listening to 01tl4tl I aired up my tires from 34 to 40 lbs and my mileage went from 28 to 30. This was at 300 miles with an average of 35 mph with no A/C on.

I will do another test but it's gettin hot again and I need my A/C!!

shooter

my 07 model tus far is ave. about 300 - 340 miles per tank, depending on the driving conditions for that tank (fillups are about 13 - 14 gal.)

troy_279

my tl is canadian and gets roughly 8 litres per 100 kms but thats all highway with nitrogen in the tires!

skippyTL

I get about 260 miles out of a tank here in Houston in a 65/35 mix of surface street/freeway.... I read somewhere on here that battery condition can affect mpg and performance. But that sounds like an "Urban Myth" - but I just replaced my battery today, so we'll see about that one!

gnl63

Hi Guys,
For a while I've been using this iPhone app that helps to track MPG. Here's the output for the past year....

IMO you shouldn't only look at MPG from what you can get in a 43 minute trip, the real measure should come from fill up to fill up. Or even better a year's worth of data...

LessisBestmakingendsmeet

Nice work, seems accurate to me.

JWTL04

Another reason why i am getting an iphone when my current contract runs out. That is sweet.

So i thought i would update the current trip. I am halfway to the beach and gone 221.4 miles and the fuel gauge is showing just over 1/2 of a tank. currently the mid is telling me that i am averaging 32mpg with an average speed of 72 mph. I love North Carolina roads. I will update with photos when i get to the beach house at the finish of the journey.

wraithvr442

Just came back from a roundtrip to Maryland from Jersey 270 miles each way. My first tank was already half gone from a trip to Trenton and back about 80 miles each way with a reset from local roads after the fillup. I got 28mpg on this fillup ran to empty until my destination where I filled up with 14.5 gallons. On paper that comes out to 29.8 mpg but I trust the cars average. I filled up when I got off the hwy and drove local streets at an average of 35mph and reset after the fillup. I got 25mpg registered the next morning when I drove home. I used a little over half a tank till I got home and saw 29mpg average before I got off the highway and read 28mpg when I pulled into my driveway. I conistantly get 19mpg driving into and out of the city in rush hour traffic where I travel less then 30 miles each way with an hour to 1 1/2 hrs each way. The car is a 2007 TL type s with 33k miles. Awesome car!

HondaOnWORKS

I don't know how much miles it takes for my TSX to burn out of gas, but I do know I get about 20s city only. I tend to hit vtec too often... =) Gotta drive with attitude!

SouthernBoy

You should be doing this anyway whenever you are traveling. There are many benefits and few drawbacks with using the car's cruise control and maintaining a constant speed.

SouthernBoy

If you are traveling on a road which has some slight hills and your speed is not that high, say under 70 MPH, and your TL has an automatic transmission then yes, there will be times when it will downshift to the next lower gear to try to maintain speed when using cruise control. For those of us who's TL's are manuals, this is a non-issue.

Still I would wager that using one's cruise control will result in an overall higher MPG when all is said and done. And there is a very good side benefit with using cruise. You tend to reduce your chances of getting a ticket because you remove the human factor on the throttle - providing you haven't set the cruise too high.

JWTL04

Ok guys i finally got the computer to work here at the beach. I averaged 38.5 mpg with and average speed of 86. I forgot to take a picture when i got off the highway. The reasaon for picture off the higway is I was only looking at highway mileage for this test. because getting into Holden beach takes 1.5 hrs since it was labor day weekend. So I was sitting in a ten mile backup of stop and go. due to the back up my MID read 16 miles to the gallon when I finally arrived at the beach house. I would have just turned the car off and enjoyed the beach air but it was over a 100 when i got here and humid as hell due to EARL. So i sat in stop and go traffic with the AC on. I have yet to stop at a gas station to fill the car up since I decided once i got to the beach house i was not going any where till after labor day. So i will venture out today and fill the car up. So stay tuned.

SmileyOr

Drove down to Crater Lake and back. Topped off the tank in Wolf Creek. From Wolf Creek to Medford, then to a friends house in Eagle point. He drove us up around the lake so the car was parked in Eagle Creek until the return trip.

I returned to Portland and drove for a day before refueling and had 364 miles on the odometer and still only put 13.2 gallons into the tank. Recorded 27.6 mpg for the entire trip based on fill up to fill up in Wolf Creek.

This was highway mileage at cruising speed (74 mph on CC most of the way). A few short sprints up to 95 mph getting away from some cars that liked to follow closely at whatever my speed was.

Overall I'm very pleased with the mileage the TLS.

SouthernBoy

Sorry, I don't buy that.

jhumbo

iTrader: (1)

Neither do I. I'd believe that at 60 MPH, but definitely not at 85. My gas mileage is about 10 lower at 85 vs. 60. (I've measure around 36mpg at 60, but only 25mpg at 85.)

SouthernBoy

I would have a hard time accepting a claim of a 38.5 MPG average under any circumstances on a trip with a TL.

SharksBreath

iTrader: (33)

^^truth.

best i've done is low 30's at a constant cruise control, around 70mph round trip on open highway. tank topped out at around 330 if i remember correctly.

38.5 mpg seems a little too good to be true. altho i wish i could get that......but no...

LaCostaRacer

There was an earlier thread in which a driver did 42mpg over 300+ miles so it is possible but I think the stars need to be lined up pretty well. The instant MPG calculation that the nav hack provides can show this fact when you doing a steady cruise at 70MPG. The problem is that you can rarely steady cruise for extended periods because traffic blocks your progress or there may be hills that need to be climbed.


Take a look at this link: https://www.fueleconomy.gov/mpg/MPG....916&details=on and you'll see that a couple drivers AVERAGE 31 MPG which is pretty good for a car of the TL's performance and size. You'll see that the best gas mileage comes from states that are mostly flat and may be sparsely populated so that interstates have a steady flow of traffic. Here in CA, it's a nightmare in most places where there is a parade formation in the fast lane and lots of weaving across lanes to go at a quick by safe pace.

In this site's sample, the average MPG is 25 and that is affected by lead foots like myself that get 20.2 in an urban commute. I think fueleconomy.gov has some of the best (although dated in some cases) data for gas mileage.

My numbers are the for the only CA car listed with an 8/18/10 update time. I seem to be the only one entering numbers for the 2006 TL at the moment. It would be nice if others could do the same against 06 or any of the other years. Think about how much time we spend on this forum discussing mileage when all this stuff could be auto-calculated by this fueleconomy.gov web site?

TheChamp531

iTrader: (3)

The person who averaged 42 MPG is BS.

Something was either wrong with his MID, or its photoshopped. The MID doesn't even add up correctly. I can see getting 42 MPG for like 5 minutes, but no way in that long of a drive. I could be wrong, but it has never happened too me and too so many members. I can get 36 mpg driving 60.

SmileyOr

I'm wondering about tire size and rolling diameter. You'd need to reset your odometer as you pass one of the odometer check sections on the highway. If you come out right on the mark, then you're probably going to be very close.

I had oversize tires on my pickup and saw lower mileage because the odometer was never corrected to the taller rolling diameter.

Getting 42 mpg on a 300 mile down hill grade would be possible. But to be fair you'd have to average between going down and then back up

Wyoming is at 7,000' elevation on highway 80. Drive west to Oregon and you drop down to 200' elevation. Theoretically it could be done somewhere along highway 80.

thrasher865

iTrader: (1)

Your statement is contradictory. Anything that affects performance without changing your fuel maps is going to affect fuel economy.

LaCostaRacer

Here's the link to the thread with 42MPG. It doesn't look photoshopped to me. I think it's possible- just improbable for most people and driving situations.

I hate cars

Not completely true. An air filter can only affect performance at the greatest air flow demands. Wide open, high rpm. It's possible you could get an immeasurable amount worse mileage at WOT. Anything below that, the TB is the restriction and controls airflow, not the air filter. MPG will be unaffected.