Worried about freeway fuel consumption recently. Getting 16 MPG... - Acura MDX Forum : Acura MDX SUV Forums
Register Home Forums Active Topics Auto Loans Photo Gallery Search Today's Posts Mark Forums Read Auto EscrowInsurance
MDXers.org is the premier Acura MDX Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools Rate Thread
Old 12-30-2012, 10:55 PM   #1 (permalink)
Registered User
 
Join Date: Oct 2003
Location: Ontario, Canada
Posts: 415
Worried about freeway fuel consumption recently. Getting 16 MPG...

So recently I took another annual trip from NY to FL and to my horrible disappointment my mileage hardly exceeded what I get in the city! I typically stayed with the traffic at about 75-80 MPH and on average got only 15-16 MPG!

Let me know what you think. Here are the circumstances and the speeds with corresponding MPG. Should I be concerned? I think I used to get avg of 21 MPG on those trips and I've taken 3 of them before with the only difference being slightly younger (lighter) kids.

The X was packed with roughly 3.5 adults (2 adults and 4 small kids below 10), some cargo (not massive amounts!) and AC was not used on the majority of the trip. The tire pressure is rather high at around 40 PSI. Air filter is new. Spark plugs have never been changed. The X has tons of power indicating good health of the engine? No problem starting or reaching any speed. Sounds very well as well. No wheels are too hot (I used to have sticking brake pads problems which made the wheels hot but I've solved them, I think, wheels are just warm to the touch)

70 MPH - 18 MPG
75 MPH - 16 MPG
80 MPH - 14 MPG

On one day I got 22MPG at 55 MPH.

Those measurements are according to the trip computer not manual check, BUT the next paragraph explains that the poor range confirms the accuracy of the trip computer.

So I am a bit concerned as I could not even get 300 miles on a tank and I felt like I am dumping gas out of a tailpipe - I think I remember getting 350 miles on freeway trips before!

Is it possible that each 5 mph is killing my MPG so much or is something wrong? I also own a new V6 sedan and such increments make almost no difference in the MPG.

It is a 2003 MDX with 140k miles on it.
__________________

LogMyMpg's Sponsor
yogi799 is offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 12-30-2012, 11:20 PM   #2 (permalink)
Registered User
 
Tyler's Avatar
 
Join Date: Apr 2012
Location: Merrimack, New Hampshire & Selinsgrove, PA
Posts: 250
Spark plugs need to be changed, out of curiosity, at what mileage did you take your trips at previously? are you putting premium in it? Between my 02 and 03 x's, I get about 19.5 mpg when cruising at 75-80.
__________________
10' Pearl White MDX - Advance Package (61,000 miles)
03' Blue MDX (209,000 miles, on it's 4th tranny.)
88' Volvo 240 - 445,000 mi.
07' Civic Si - Sold
02' Black MDX (totaled by a deer in PA)
Susquehanna University Alumni
Tyler is offline   Reply With Quote Quick reply to this message
Old 12-30-2012, 11:27 PM   #3 (permalink)
Registered User
 
Join Date: Oct 2003
Location: Ontario, Canada
Posts: 415
114 k and 127 k

No, regular gas. I believe I used regular in the last 3 trips as well though...
yogi799 is offline   Reply With Quote Quick reply to this message
Old 12-30-2012, 11:40 PM   #4 (permalink)
Registered User
 
Join Date: Dec 2012
Location: Jeffersonville, Indiana
Posts: 25
Quote:
Originally Posted by yogi799 View Post
114 k and 127 k

No, regular gas. I believe I used regular in the last 3 trips as well though...
I have a 2001 and I noticed a major loss of MPG when I tried to use regular unleaded. Oh and for the record, I am spending 3/4 of a cent LESS per mile using premium versus regular unleaded.

INGunGuy
INGunGuy is offline   Reply With Quote Quick reply to this message
Old 12-30-2012, 11:45 PM   #5 (permalink)
Registered User
 
Join Date: Oct 2003
Location: Ontario, Canada
Posts: 415
I hear you guys but the fact is that I used to get about 20 MPG on regular and now down to 15-16. Would spark plugs make any difference (the engine seems to perform well, except the MPG)?
yogi799 is offline   Reply With Quote Quick reply to this message
Old 12-31-2012, 12:04 AM   #6 (permalink)
Registered User
 
Tyler's Avatar
 
Join Date: Apr 2012
Location: Merrimack, New Hampshire & Selinsgrove, PA
Posts: 250
Yes, spark plugs would make a difference. I believe Acura suggests to change the iridium spark plugs at 100k. I prefer to change mine every 60k, but that is my personal preference. Plus carbon build up can happen around the sparkplug which can make it a real bear to take out. A buddy of mine did not change his on his Nissan Altima (2008) and wanted me to change them at 165k and they were baked right it Lol.
__________________
10' Pearl White MDX - Advance Package (61,000 miles)
03' Blue MDX (209,000 miles, on it's 4th tranny.)
88' Volvo 240 - 445,000 mi.
07' Civic Si - Sold
02' Black MDX (totaled by a deer in PA)
Susquehanna University Alumni
Tyler is offline   Reply With Quote Quick reply to this message
Old 12-31-2012, 12:05 AM   #7 (permalink)
Registered User
 
Join Date: Dec 2012
Location: Jeffersonville, Indiana
Posts: 25
Quote:
Originally Posted by yogi799 View Post
I hear you guys but the fact is that I used to get about 20 MPG on regular and now down to 15-16. Would spark plugs make any difference (the engine seems to perform well, except the MPG)?
Yes, the spark plugs are not firing as "hot" as they should so your fuel economy suffers. Also as for using premium unleaded, the fuel economy gained outweigh the cost difference.

INGunGuy
INGunGuy is offline   Reply With Quote Quick reply to this message
Old 12-31-2012, 12:09 AM   #8 (permalink)
Registered User
 
Join Date: Oct 2003
Location: Ontario, Canada
Posts: 415
What puzzles me is why the heck am I able to get 21-22MPG at 55mph and the mileage tanks at higher speeds if the spark plugs (or anything else for that matter) is not right?

And yes, I wanted to start using Premium again but in Ontario the price difference is huge and I did not know if it's worth it...
yogi799 is offline   Reply With Quote Quick reply to this message
Old 12-31-2012, 12:22 AM   #9 (permalink)
Registered User
 
Join Date: Dec 2012
Location: Jeffersonville, Indiana
Posts: 25
Quote:
Originally Posted by yogi799 View Post
What puzzles me is why the heck am I able to get 21-22MPG at 55mph and the mileage tanks at higher speeds if the spark plugs (or anything else for that matter) is not right?

And yes, I wanted to start using Premium again but in Ontario the price difference is huge and I did not know if it's worth it...
If the spark plugs are worn out it really starts to show at higher speeds where the engine is working harder. I say it is high time for a spark plug change. I have a 1997 Ford Escort that I was getting 32 - 35 MPG at 80 MPH I dropped to around 28 MPG I pulled the plugs and they were shot. I changed the plugs, and immediately my MPG went to 32 - 35 MPG at around 80 - 85 MPH. If I were to keep my speeds to 65 MPH, I was getting around 35 - 36 MPG so the gain for the speed reduction wasnt worth the extra time on the road. I travel 60 miles one-way to work every day so I try and keep my speed a bit higher since I do it every day...

INGunGuy
INGunGuy is offline   Reply With Quote Quick reply to this message
Old 12-31-2012, 12:24 AM   #10 (permalink)
Registered User
 
Join Date: Dec 2012
Location: Jeffersonville, Indiana
Posts: 25
Quote:
Originally Posted by yogi799 View Post
What puzzles me is why the heck am I able to get 21-22MPG at 55mph and the mileage tanks at higher speeds if the spark plugs (or anything else for that matter) is not right?

And yes, I wanted to start using Premium again but in Ontario the price difference is huge and I did not know if it's worth it...
Another thing that I have noticed is that if I set the cruise in my 2001 MDX I get around 24 - 25 MPG at 75 MPH which kind of surprised me. But if I try and keep the speed at 75 without using the cruise I am getting 21-23 MPG... which is another surprise.

INGunGuy
INGunGuy is offline   Reply With Quote Quick reply to this message
Old 12-31-2012, 12:29 AM   #11 (permalink)
Registered User
 
Join Date: Oct 2003
Location: Ontario, Canada
Posts: 415
OK, thanks. I am reading other old threads and see a variety of reports. Some ppl get 20+ at 75mph, some get 16 like me now. Weird. I always use the cruise.

I already got new spark plugs and will change them asap. Not to hijack my own thread, but am I looking at a nightmare of a job since it's got 140k on the clock? Should I do anything special when replacing them OR can they break if I apply to much force to loosen them up? Last thing I want is to damage my engine because of this simple omission.
yogi799 is offline   Reply With Quote Quick reply to this message
Old 12-31-2012, 12:34 AM   #12 (permalink)
Registered User
 
Join Date: Dec 2012
Location: Jeffersonville, Indiana
Posts: 25
Quote:
Originally Posted by yogi799 View Post
OK, thanks. I am reading other old threads and see a variety of reports. Some ppl get 20+ at 75mph, some get 16 like me now. Weird. I always use the cruise.

I already got new spark plugs and will change them asap. Not to hijack my own thread, but am I looking at a nightmare of a job since it's got 140k on the clock? Should I do anything special when replacing them OR can they break if I apply to much force to loosen them up? Last thing I want is to damage my engine because of this simple omission.
They should not be too difficult to remove... Just dont force the issue...

INGunGuy
INGunGuy is offline   Reply With Quote Quick reply to this message
Old 12-31-2012, 01:01 AM   #13 (permalink)
Registered User
 
Tyler's Avatar
 
Join Date: Apr 2012
Location: Merrimack, New Hampshire & Selinsgrove, PA
Posts: 250
They should be okay, if there is a lot of buildup I prefer to use Marvel's mystery oil and let it soak for a bit, then come few hours later. It works to loosen up the buildup, but I think you should be okay with out it. Remember always start the spark plug by hand (using extension) that way you will not strip the threads. Righty tighty lefty loosey...
__________________
10' Pearl White MDX - Advance Package (61,000 miles)
03' Blue MDX (209,000 miles, on it's 4th tranny.)
88' Volvo 240 - 445,000 mi.
07' Civic Si - Sold
02' Black MDX (totaled by a deer in PA)
Susquehanna University Alumni
Tyler is offline   Reply With Quote Quick reply to this message
Old 12-31-2012, 01:05 AM   #14 (permalink)
Registered User
 
Join Date: Oct 2003
Location: Ontario, Canada
Posts: 415
Maybe a dumb question, but I am about to leave FL back for up north tomorrow... Would it hurt in any way if I just got the three front ones replaced? I may simply run outta time to do all six. Or better not do any OR all at once?
yogi799 is offline   Reply With Quote Quick reply to this message
Old 12-31-2012, 01:50 AM   #15 (permalink)
Registered User
 
Join Date: Dec 2012
Location: Jeffersonville, Indiana
Posts: 25
Quote:
Originally Posted by yogi799 View Post
Maybe a dumb question, but I am about to leave FL back for up north tomorrow... Would it hurt in any way if I just got the three front ones replaced? I may simply run outta time to do all six. Or better not do any OR all at once?

I would take the time to get all 6 replaced. I myself in all the years of shade-tree mechanics that I have accomplished have never not replaced every spark plug. Also to make the next removal a little easier, put some anti-seize compound on each plug.

INGunGuy
INGunGuy is offline   Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Reply


Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Acura MDX Forum : Acura MDX SUV Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Random Question

Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -4. The time now is 05:13 PM.



Powered by vBulletin® Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
SEO by vBSEO 3.3.2
Copyright 2000-2010 MDXers.org. All Rights Reserved.