bradykp

Anyone else experiencing this? My gas mileage on the highway used to be about 32mpg in the early stages. Now, even with cruise control going around 70mph, I cannot seem to break 29.5, usually even below that. It's the same route from NJ to PA that I use to compare, so the road conditions should not be different. If anything, the recently paved sections should help me, not hurt me. Any thoughts on why my mileage could be dropping? I check tire pressure, so that's not it. I can't think of any other littler things to do, but I'm willing to try anything for even small improvements.

rmjames007

I have noticed the same with my car in street driving but I also figure that it makes a difference where I get my gas

club_euro2

I would try some amoco gas. Amoco ultimate.

TS_eXpeed

Kind of like what they said. Upgrade to premium gas for a few tanks (if you are not using it already) and go and buy bottle of the fuel system cleaner/fuel additive from autozone (or a place of the likes) to put in your tank and then really push the car in the tank you have the additive you have. It should do the trick.

hunterk1

I'd say you're noticing the higher amount of oxygenates put in fuel in the winter but you should have seen that a while ago. Maybe the gas you bought recently had more ethanol in it than usual (did you go to an unusual station)?

Seems like OEM tires start to wear out at 40k - maybe your tread is wearing down and you have more rolling resistance?

Who knows...? I've seen this happen to me once on my 18k miles car and I just waited it out... something was in the atmosphere that month...

Reach

Couple factors: some fuel system cleaner additives can help (detergents), I don't do it as often as others, but 1 bottle every oil change seems to work. older / balding tires can hurt mpg too as your rolling resistance coefficient increases.

Now that I read it... what hunterk1 said. +1.

jlukja

^^ + check alignment

nj2pa2nc

My 06 6MT averages 32-36MPG (mostly highway driving). I try to buy my gas at WaWa or at Sam's club. My car, bought new 11/17/06, has almost 42,000 miles. I get the tires rotated and balanced between 6,000-7000 miles and check the tire pressure on a regular basis. The stock tires still have alot of thread on them and should last at least 8,000-10,000 more miles.

EuroR08

Have you ever replaced your fuel filter or changed your air filter?

jlukja

^^ fuel filter replacement is not a DIY job.

DuckDodgers

Not technically true...I read the procedure in the Service Manual and could do it, but like you imply, it's a bear.

EuroR08

even if u pay someone to do it for you - it should majorly help your gas milage...

bradykp

study after study has proved that brand of gas does not affect mileage. i have tried all kinds of brands, i've tried 91 vs 93, and the difference between 91 and 93, if any, is negligible.

i usually fill up with sunoco 91 or BP (which is amaco).

bradykp

i've noticed this over a period of about the past year. i have already replaced the OEM tires, i think it's the comparable goodyear brand, forget the model.

bradykp

i hit a NJ pothole at 25,000 miles and had a flat. come to think of it, because of that, one of my rims is slightly bent, which means they had to add weights to re balance, which could easily be my problem....hmmmm. stream of thought typing.

anyways, i'm going to double check when the last time i had the tires rotated. i think i'm right around the 7,000 mile mark now, and that could simply be it. only problem is, sam's club doesn't do alignments (that i know of), so i'll have to go somewhere else.


does anyone think it's worth getting a new rim to replace the bent one? it's very slight, according to the tire guy

bradykp

actually, no, i skipped it at one of the maintenance intervals, and forgot to do it since. i don't know how to change the fuel filter or air filter myself, though i keep telling myself i'll look it up and go to NAPA and buy them.

anyone that can provide me a description? i'll also search. i also need to change the cabin filter.

bradykp

do i have to have the dealer do it? i could have my dad's mechanic at home do it, i haven't found anyone in hoboken, nj i trust yet.

jlukja

^^ check the other thread. The fuel filter is really just a fuel strainer, but its located inside the gas tank. Its not meant to be user replaceable and is not part of any maintenance schedule. SoCaliTrojan found a reference quoting that the fuel strainer is good for the life of your car.

On another topic, and just food for thought, this past Christmas my brother gave me a membership to Costco. So, over the past 3 months I've been filling up with Costco brand 91 octane. My mileage has dropped by roughly 2 mpg in this time period. I thought it might have been the weather, the winter formulation, my tire pressure, etc. But, last weekend we drove down to San Diego and I filled up at Shell and my mileage is back to "normal". So, I think that there may be a difference among brands, and if not brands then maybe this particular Costco station just carries bad gas.

bradykp

i've used costco gas a couple times over the past 6 months, you don't need to be a member to buy their gas in NJ, and it's 30 cents cheaper than everywhere else, so even if i lose 1-2mpg, i am coming out ahead, but anyways, i've also used Sunoco, and BP, 91 and 93, and i really haven't been able to break back up into that 32-34mpg i got (strictly highway) in the first 20,000 miles.

i do need to change the air filter and the cabin filter, but i don't think either of those things will help.

you're saying there is no reason to change the fuel filter?

i'll rotate the tires and take it somewhere for an alignment. i'll also pick up some additive to put in the next fill up. we'll see.

club_euro2

I would try the bg 44k fuel treatment.

nj2pa2nc

i'll rotate the tires and take it somewhere for an alignment. i'll also pick up some additive to put in the next fill up. we'll see.[/QUOTE]


I would first get the tiresrotated and balanced-you might not need the alignment.
I replaced air and cabin filters at about 27,000 miles-MPG stayed the same.

jlukja

Yes. Acura's position is that it doesn't need changing and I'll agree. First, its probably a PITA considering where it is mounted. Second, even if it was clogged a little it shouldn't affect your fuel economy unless it was so clogged that the pressure drops and the fuel injectors do not deliver the proper amount of fuel. If that were the case I would imagine the ECU would note that and the CEL would come on. I think a fuel additive should be your first step, let it try to clean out the filter, the fuel lines, and throttle body, and the injectors.

bradykp

I would first get the tiresrotated and balanced-you might not need the alignment.
I replaced air and cabin filters at about 27,000 miles-MPG stayed the same.[/QUOTE]

that's around where i got the maintenance minder for that. i figured i'd do it myself, and at 39k, i haven't gotten around to it even though NAPA is 4 blocks away.

i will rotate/balance first and see what happens. starting this thread made me realize i was probably close to needing that as i started to type.

alignment will be step 2. i'll throw in the additive just for good measure.

bradykp

goog call, thanks!

CiViCKiDD

lol am i the only one who notices he always mentions the date he bought his car, that he has a 6mt, and current mileage? guess you really love your car...

1Louder

Only if the brand uses an ethanol blend when others don't. But apples to apples, I'd agree. Our Shell stations around here only sell E10. Sometimes a station will switch and may or may not say anything about it.

For the OP - all good tips here. I'd maybe try another gas station. I would not rule out tires or alignment. Did you recently use a different type of oil?

SodaLuvr

That's probably why.

The OEM tires usually have very good rolling resistance (and often at the expense of noise, grip, etc). Replacement tires tend to better in the areas of grip, but they are rarely low rolling resistance tires. This can cause a huge drop in fuel economy.

bbznyc

What's up bradykp...

I haven't heard you for a while hommie... Remember our purchase back in '05???

I miss my crazy thread "how much you paid for your 2006???" ahahah

Anyway, i have the same issue with 45k on the car.... Gas milage is crap... My friend on 330xi has better milage. It's pathetic...

I dont know what to do...

Plus accelaration on the car got worse, takes forever now....

GenXY2k

have u already switch to synthetic oil ?? i did it at 25k and my mpg went up a bit.. like 1 or 2 .

feuss2

iTrader: (1)

change your spark plugs...

davidspalding

Bradykp, the air filter is a easy-peasy job, certainly DIY. Also, the manuals are online, look in the FAQ section.

SodaLuvr

I would definitely change the engine and cabin air filters if you haven't already done so. The air filter can have a huge effect on the MPG. Some people claim that a clogged cabin air filter could potentially affect fuel economy as well, as the electric fan motor would have to work harder to push the air through the HVAC system, which could cause a drop in fuel economy. Not sure if I buy into that, but I'd still change the cabin air filter as those tend to look fairly nasty after 15k.

jswim99

I, too, noticed about a 3-4 mpg drop with new tires (I now have Yokohama Avid V4S).

bradykp

i'm not convinced it's the tires. it is the comprable goodyear model to the michilins, and from what i have heard about the mich's, they were pretty crappy. plus, it didn't happen for the first 5k or so the new tires were on.

i did just get the tires rotated and they told me the rear tires were wearing unevenly, so i am taking it in for acura to look at the alignment and the rear shocks.

SodaLuvr

The Michelins may be crappy as far as grip goes, but the OE Michelins tend to have extremely low rolling resistance compared to aftermarket replacements.

godfather2

like many other people, i put in a bottle of $3 stp fuel injector cleanor every 3rd or 4th trip to the gas station. i HAVE NOT noticed any drop in mileage over the past 60k miles

danslvpt

comes to think of it...my 05 auto just turn 45000 miles and the milage i am getting is 23mpg on the free way??? I drove about 75 mph with 2 adults and 2 kids. It shouldn't get down that low....90% free way and 10% local. I had new set of tires...Falken ze ex 512, they are noisy.

bradykp

i still have to disagree about the tires. i've spoken to mechanics, and other car enthusiasts about this (who happen to be engineers), and it really makes no sense. if the tire did offer more resistance, the power required to start them rolling would be greater by a slight amount, but it would also propel the car further because more grip would be less slip.

regardless, it cannot be the tires, since i've experience the good gas economy with these tires for at least 5k miles.

took the car in today for alignment, they said it did need it.

bradykp

were you driving significantly faster than normal? i get a significant drop above 75mph.

bradykp

so we took the car for an alignment today. this is my first car that i am responsible for, so i'm not familiar with all maintenance costs. wondering, is the $99 acura charged us outrageous for the NY metro area? we're in jersey. i've heard i probably could get it done for $75-$85, but that's not a difference worth shopping around for when the car was already at acura