Skirmich

Well after now 4-5 tanks of premium on my 07 MDX.
I've got this to say... This thing LOVES Gas hahaha..

When I first got the car I was getting steady trips of 13/14mpg city which was under the stated MPGs from fueleconomy.gov I suspected the spark plugs where at fault and indeed, After the maintenance specially the spark plug change MPGs got a bump to 16/17mpgs city driving similarly as when I was getting 13/14mpg, And that is why I don't trust 100K spark plug changes regardless of brand.. The Denso spark plugs showed clear sign of wear and I believe those were the stock 72K plugs.

From my driving impressions it seems the mpg gets a hit if I drive like I stole it.. Dipping to 11mpg when driven hard. If I were to totally baby it from stops and caring for absolute mpg efficiency the best I've got is 18.5mpg city. That is a mix of 40mph speed limits and stop and go traffic +A/C.

Hwy has been less affected after the maintenance. Was getting 20-21mpg when I got it, After the maintenance I am getting a best of 23mpg under 70mph... I wish I had the mpgs from my TL-S on it but I was prepared for this kind of mpg performance.


So how is your MPG?

Carpayment4life

Try a site named fuelly dot com

Other than that, the specs on denso plugs vs ngk plugs show a slight ngk advantage.

My 2007 mdx, with ngk gets 16 mpg around town.

Skirmich

^That is full stop and go or combined with speed limit straights? cuz in full stop and go (Heavy Traffic) I get around 14-15mpg.

Mr. Merky

iTrader: (1)

Coming from a 2nd Gen TSX with 27 mpg then 24.5 mpg after putting 19's on it, my 2nd MDX is definetely thirsty at 17.7 mpg. I just put some 20" Stance wheels 2 weeks ago and my mpg dropped to 17.5. These are rotary forged wheels so they are lighter. I'm hoping my mpg wouldn't be that bad. I use Lucas Fuel injector cleaner which is suppose to help the mpg. Only time will tell.

Mr. Merky

iTrader: (1)

By the way, I baby it to get 17.5 mpg

Skirmich

My TL-S gets me 31mph hwy and 23-24 city depending on traffic..
The hit from the MDX mpg was a considered set back but I don´t mind it that much anymore, but at least don't want to underperform the stated mpgs.

Skirmich

If I totally grandma mode I get consistent +18mpg with combined straights + stop and go. My all time worse was 11mpg but that was getting out of stop signs in a hurry.. I firmly believe getting the MDX moving is the biggest hit for MPG..

My next step is the obligatory Underdrive crank pulley to help those 1st gear starts, It was an amazing mod for my TL-S..
I expect it to be as good in the MDX, specially for those stop and go situations.

mrgold35

I'm usually around 14-15 mpg in 100% city driving. I only get this when I'm in Las Vegas or LA with almost zero hwy miles. In my hometown, I usually get 17-18 mpg combined with about 60-70% hwy with speeds of 70-80 mph range. I can squeeze out around 20-22 mpg on the hwy with the cruise set to 80 mph (depends on the amount of hills and downshifts). I can get around 27 mpg on my TSX and about 19-20 mpg on my RDX in the same hometown daily driving. The MDX really hates city driving. I usually don't take it around town to run errands unless I need the extra space.

I did 20" rims in Conti DWS tires; but, my before/after mpgs stayed about the same (less road noise with Conti DWS compared to OEM).

I'm coming up on 70,000 miles on the MDX and was thinking about switching out the spark plugs early because I think 100,000 miles is way too long to wait. It made a noticeable difference on my TSX once I did the plugs on the 100,000 miles service.

Skirmich

^ I truly recommend changing the spark plugs early.. 100K is way overboard and I think Honda only states that to keep the motto "100K Maintenance Schedules Car" because at least the stock Denso plugs will never reach that alive.

Since I bought this car used I don't know what the stock tires were..
Mine is Riding Michelin Latitude Tour HPs, So far they truly suck at cornering (Tons of screeching) but traction is good while off/roading and in rain.

nats007

We've owned our X coming up a year now with an average mpg is 15.2-15.5 mpg with mixed city/hwy. For the first 6 months, I tried to keep the MPG above 16, but it's very challenging.

Overall, it does guzzle gas w.r.t. sedans, but I've stopped trying to conserve gas and started enjoying it for what it is... a fun, sporty, SUV and I can't complain as 15 mpg is not too bad!

Skirmich

Its weird because I can keep it above 16mpg without a challenge but it drives painfully slow... I mean, I had Beatles overtaking me and more than a few people flashing me because I was obstructing traffic specially coming out of a stop sign... If I gain speed slowly I can drive normally in the 60mph region with little to no penalty in mpgs..

Today I totally forgot about being careful with the gas = 13mpg But I enjoyed every freaking second of it.

mrgold35

I feel the 3.7L might be a little under-powered for the 4500-5200lbs/sh-awd of the MDX. I live and travel above 5000ft and that also takes some HP away. The engine has to work so hard pulling that kind of mass from a dead stop makes it really drink the gas. Once it gets going, you can see up to 23-24 mpg on the hwy at 65-70 mph. Putting the +14 MDX on a diet was step in the right direction and the introduction of the 9AT+cylinder deactivation was another couple of steps.

I wish aftermarket support was there for Acura/Honda engines. A bolt on supercharger to add another 50-70 HP would make the MDX perfect power wise and might even improve drive-ability and mpgs. Better yet, add the sport-hybrid-sh-awd to the +17 MDX to help with low speed acceleration/handling and city mpgs. I think folks with the +14 MDX are seeing the low end of mpgs in 100% city driving also.

Skirmich

^ Talking about performance I was checking all the exhaust mods for the X..
But holy christ: To get Pre-cats, J-pipe, High Flow Cat and Exhaust is hovering in the +2K range....

And I totally agree.. Even with 300hp the J37 is a tad underpowered... I wish Honda could just get with the program and release a J40 for the MDX only, It really needs it to be more competitive but I guess performance isn't on their priorities.

A J40 with 340hp will be enough to keep lunatics like us happy and don't harm the mpgs that much for the soccermoms.. Sadly with the new SH-AWD being that much VTM4-ish I think I will pass on it... Unless Acura ships it with the real Full Time mechanical system again.

Skirmich

Today I managed to squeeze 25.2mpg in a +60mile night trip @ 50mph and it was getting better, I think I could pushed to 26mpg if I dropped to 40mph but it was too slow to my taste.
Sorry for the crappy pic but I was alone and the iPhone wasn't cooperating (Also Spanish Dash like a boss).

mrgold35

I got close to that once with a stiff 25-30 mph tail wind on the hwy with my X. Then on the way back home with the same 30 mph spring breeze as a headwind, I managed about 15 mpg.

Skirmich

It was funny because before filling her up (And thus resetting the trip) I was doing 11.2mpg in the city I just want to get up and go...

After all the oils and spark plugs and obviously the K&N filter adding about 15hp the car feels more snappy and I just get out of stop signs at the speed of the other cars (RPMs @ 3-4K) and the car just shoots once it gets out of 2.5-3K RPM.. But feels like 3-4cyl if I just care for mpg and never exceed 2.5K at least If I do that I am getting consistent 17.5mpg to 18 in some mixed driving.

Skirmich

Well yesterday this happened


Went on like that for 20 miles at 60mph..

nats007

^ impressive... Unfortunately, I'm lead footed. Best I get is 15.7 mixed and I cruise on the highway between 70-82 mph

technocrat

Interesting thread, i often tell my friends that the MDX has no fuel saving technology lol :p

I see anywhere from 13.4 to 16.x in city mostly lower. On Highway max i have seen is 21.x but I must admit I do have a heavy foot & most of the city runs are very short.

Skirmich

Well it doesn't at least AFAIK the J37 never came with VCM or any other form of ECO tech.
If mine had the VCM who knows? Steady +25mpg quite possible?
I think since VCM was introduced with the 6 speedo I cant really see VCM being that big of a factor for MPGs more than the extra gear in the trans...

This is key in my friends Accord Coupe V6 2010 Auto with VCM but still with 5 gears.
He gets constant 24-26mpg on highway.. Which is not that far impressive as it should be running on only 4cyl in the hwy, His car uses Regular though so that is a big saving too.

csmeance

MDX gets about 21-22 on the highway, 14-17 in the city depending on how heavy traffic is such as Miami vs Daytona Beach. Used to get about 1-2MPG more.

To the OP, NGK plugs are much better. My MDX has 100K on OEM plugs & timing belt and such, filter was replaced at 90K.

Try running a fuel clean like redline SI-1, it gave me back a nice MPG bump.

Skirmich

Ill try with a can of Seafoam to the tank if it gets any better.. But right now I´m pretty satisfied with the mpgs, If it gets any better then its welcomed.

technocrat

Yes, I know no VCM in the 3.7, I had a 2008 Accord V6 Sedan with VCM before the MDX & I once achieved 29.6 mpg on highway(regular was 26-28), city was 18-23 depending on traffic & how I drove.

With current gas prices its ok but if they go back to $3-$4 that's when it will start pinching.

mrgold35

I fueled up the other day and it was $1.979 for 91 octane at Sam's club. I would take a trip in the MDX if I wasn't so broke after the holidays and used most of my vacation time. Gas prices will probably jump up when I'm ready to travel in the spring time.

Skirmich

^ Like it always do right?

Well here in So-Cal its crappy 3.25 bucks to 4 bucks for Premium so I am still kinda stuck in the depression....