16mpg How Can I Improve??

[Clyons0203]

I just recently replaced and changed my oil and air filter and also bought brand new OEM sized tires and decided to test the car to see how bad on gas it was.

$60 worth of premium gas (20 gallons) lasted me 320 miles. So 16mpg. This was with mixed driving. About half highway cruising (75-80mph) and half city driving.

The car came rated at 17city and 22 highway. How can I improve my mpg?? I already have the nico ecu which i thought had a run lean while cruising feature or something like that.

[Jesda]

What is the year and mileage of your Q?

[paranoidjack]

buy a honda!

Those ratings from the factory are under OPTIMAL (nonexistent) conditions. Only if my grandma drove my q MIGHT she see 20

[Q45tech]

I know you'll laugh but Greensboro is way too urban for the EPA 1985 test.Rural city or rural highway.

Did you drive faster than 59-61 mph, did you accelerate faster than a snail, did you turn AC on during the test.

Does your gasoline meet the standards of the 1985 test and does your gasoline meet the as designed Japanese fuel quality? No oxygenates and have 125,000 btu per gallon.

Even assumming a perfect Q [oem compression and leak down] you can expect a 2-4 mpg decrease below the sticker rating if any of the above where used/done while testing.

Raliegh/Durham/Greensboro appear to be getting ethanolized fuel is this correct? "7.8 RVP North Carolina Counties: Gaston County Mecklenberg County Davidson County Davie County Forsyth County Guilford County Durham County Wake County Granville County " Visit your Charter-Triad Terminal and find out!

[ddrumman]

I just recently replaced and changed my oil and air filter and also bought brand new OEM sized tires and decided to test the car to see how bad on gas it was.

$60 worth of premium gas (20 gallons) lasted me 320 miles. So 16mpg. This was with mixed driving. About half highway cruising (75-80mph) and half city driving.

The car came rated at 17city and 22 highway. How can I improve my mpg?? I already have the nico ecu which i thought had a run lean while cruising feature or something like that.

Consider yourself lucky.

My Q is getting 12.5 to about 15. %wise 60city/40hwy.Dealer serviced all its life.

[elwesso]

16-17 is about as good as youll do with mixed driving.....

If you can still get 20-22 on the highway your Q is fine. and you probably wouldnt be able to do much.

[Jeff Williams]

22 MPG at 70 MPH, IF you don't try to pass anybody, or get stuck behind a truck going up hills.

20 MPG at 78 MPH, IF you don't do any WOT runs.

19 MPG at 82 MPH, with a couple WOT runs.

15 MPG at city driving, easing away from each stop light, and not idling in drive-thru windows.

12 MPG at city driving, racing every freakin thing from light to light.

Hopefully, you will fall somewhere in between these numbers, based on your driving habbits.

[litlchi]

Haha, the only person I've ever seen being able to consistantly get over EPA mileage is my mom...then again, she drives a manual transmission, lets the car drift as far as it will take her in neutral towards stop signs/red lights, accelerated slower than me pushing the car, and doesn't use A/C even during Houston summers !

[louiegz]

I use to think there was something wrong with my car because I normally get about 10 miles to the gallon for the normal city driving that I do. Hell, two fillups ago, I got 9.7mpg. There're a lot of hills where I live. I also do a lot of short drives, 3 miles to work each way. The thing that is leading me to believe my car runs normally is that when I did my last long road trip, witch was about 1500 miles roundtrip, I averaged between 19 and 21mpg, and that was doing about 80 mph most of the way. At one point of the trip, I did 270 miles in 3 hours. Those would be normal mpg numbers. So be glad you don't live in a place with all those hills, like me.
Modified by louiegz at 1:00 AM 6/20/2006

[deepsouthq]

i won't complain-17.5 in town, 21.5 hwy- but i would like better !!!new murano rims and 235/50/18s tomorrow w/ new oe struts, can't wait.

[Skibane]

Haha, the only person I've ever seen being able to consistantly get over EPA mileage is my mom...then again, she drives a manual transmission, lets the car drift as far as it will take her in neutral towards stop signs/red lights, accelerated slower than me pushing the car, and doesn't use A/C even during Houston summers !

Well, I ain't yer mom, but I'm consistently hitting 17+ in hot, AC-running-full-tilt San Antonio city driving, and a solid 24 on the highway at 70 MPH - with nothing special about the driving style.

Considering the car's other virtues, I have absolutely no complaints about the mileage whatsoever...

[Jesda]

19.9 from STL to Indy at a steady 80mph with AC. Thats the best I've personally ever seen from a Q45. On the way home, however, I eeked out 16.9 doing 90-100.

I think the ECU helped with highway mileage. In town, I get between 13 and 15. I think the '90 is a wee bit lighter than 91-93.

Basically, your fuel economy will always suck. Make sure your O2 and knock sensors are good, keep your injectors clean, and use quality gasoline without ethanol if possible.

[Clyons0203]

94 with 135k miles.

[Falkdesigns]

Y33 numbers are very similar. I can get a solid 20 mpg from L.A. to Las Vegas @ 85 w/ AC on, while I get like 13-15 around town (more like 12 most of the time, my foot is too heavy, hehe).

[Q45tech]

Assumming you are running in closed loop [steady speed] [and not traveling in big hills] even up to 100 mph the O2 are telling ecu what to do to maintain 14.7 AF or 14.13 AF with ethanol.

ECU mods don't affect this critical area...........low load.

[fairplay]

I have 2002 Q45 with 83,000 mile on it. There was a mode I did where it took the lag out of acceleration. I get 17mpg with A/c running in town. Tried without A/C running windows down and I got 21 mpg in town. Did not try freeway driving yet.. Strange why such a difference. I am suprised some of you guy are getting such poor miles. I use WIX brand for all filters.

[BadQ45t]

The 2002 is a completely different model so not a big deal that MPG is different. Bottom line NO Q45 is a big MPG player. I get about the same the Falk does in his 98' in my 97', I can get solid low 20's on the highway, I actuallly get 20 solid driving in the Bay Area, but in LA driving it is down to 15-17 right away, just too many WOT from stop signs and not enough open freeways.

[infinitinut2]

During trip to San Antonio from SW NM mountains for 4th Holiday, I got 21 mpg on one tank of Chevron 91 in my 92Q w/ 134K, cruising at constant 88 mph (80 mph speed limits on Texas I-10!) with a/c on. Now, on one tank fron Ft Stockton to San Antonio, I know it had to be in the high teens, but I did not have courage to check it! This tank was with speeds NEVER below 100 mph, mostly at 110-120! The mighty Qship now sits under her cover back in NM, waiting for her next chance to go out and play!

Too many vehicles (5) makes me consider selling Q, but, checking KKB value, makes me determined to burn it before letting it go for that price! This is the Q that Q45 Tech/aka Dennis called "one of the best examples of an original Q that we have seen at T-3" when it was over for guides, etc., in summer of 2000!

[sdkhalsa]

94' Q 100K. 16.5 mi/gal with heavy(Arizona) AC. Light on pedal. About 20 at 75mi/hr. highway.

[infinitinut2]

...sorry, LOW teens on the one tank, NOT high teens! (I should read closer before posting!)

[texasoil]

Q45 fuel economy is drastically impacted by more than light acceleration. A light foot and watching lights ahead , adjusting speed to avoid sitting-can increase your 'city driving' MPG to high teens from low teens--and get you there just as fast.

Steady freeway cruising at 70., A/C on ,95 ambient, no head wind, should yield 21-23, depending on tires and road surface--takes more fuel with wider tires & grooved concrete over stock size tires, max psi, smooth asphalt. BTW, the belly pan is worth almost 1.5 MPG at 70.

[0wn3r]

didnt read everything... but try filling your tank halfway.

i'm keeping my 240 at only 10 gallons now... saves a little weight. i believe alot of people that race do the same.

[elwesso]

didnt read everything... but try filling your tank halfway.

i'm keeping my 240 at only 10 gallons now... saves a little weight. i believe alot of people that race do the same.

that is reasonable advice... I notice that on my Q i get much better mileage after 1/2 tank.....

[xmateo]

I am getting about 19/22 mpg with premium. It was around 16 mpg with regular unleaded. I drive a good mix of city/highway and relaxed/quick driving.The recent change to premium also improved acceleration performance in my 99 Q. However, the 110 degree Phoenix heat is really zapping the quick acceleration right now.

[DrewQ45]

We are driving 300 HP sedans with high performance V-8 engines, many of us running with upgraded ECUs. Fuel frugality obviously wasn't a consideration at the time of purchase. I can't drive the Q like an old lady... it defeats the purpose of having one. I say buy a manual 4-banger and avoid downshifts if you are looking for good mileage.

...Drew...

[ddrumman]

BTW, the belly pan is worth almost 1.5 MPG at 70.

Wow!!!!That explains my 12.5 to 13 mpg lately (mostly city). I would have never thought of that. But then again I'd have never thought of a lot of things that I have learned by just being a member of this GREAT club.