Since I bought my 2004 MDX I couldn't get anything better than 14 to 15 MPG in the city no matter how easy I was on the gas pedal. I use my MDX as my work truck and as my daily driver (I have an 03 CL-S that's more of a race car so it just sits in the garage for the most part). I decided to shed some weight off the MDX by removing the middle row seating. The middle row seating weighed almost 200 lbs! It's just me and my girlfriend so we never use the middle seat let alone the rear seats. And if we have 2 other people in the MDX they can sit in the third row seating and it's like a limo back there without the 2nd row seating. With the third row seating folded down I have TONS of cargo room now, which benefits me more with work. I also added an intake, deleted the butterfly valves in the intake manifold, and hollowed out the catalytic converter. Now if I drive normal I get 17 to 18 MPG and if I really try hard to get the best MPG in the city this is what I get......(remember, this is strictly City driving)

 

"and hollowed out the catalytic converter"
There is your gains..

 

Oh lord! I guess that's a tiny bit low, but not much...


They do much better on the highway... That's how all j series V6 engine are mostly...


MDX being the worst on gas...



Maybe new spark plugs, 3x3 tranny drain and fill (do NOT flush), air filter... Basically, check everything out... You may get 1-3 mpg back!

 

I'm just curious what everyone else is averaging in the city. Everyone seems to complain how bad the gas mileage is on these vehicles. I thought for those little mods i did to the MDX made a really good difference on a 170k MDX. When I mentioned earlier that I was getting 14-15 mpg that was really trying to feather the gas pedal as much as I could. There were plenty of times that I was getting 12 mpg. Now if I drive like that I get about 20 mpg. I'm sure when the MDX was new it was closer to it's suggested mpg, but I'm happy with it now.

 

The cat mod made all the difference, Its very restrictive and Honda J Series benefit from free flowing exhaust… If you could do headers you could gain more MPGs, But IIRC the 04 doesn´t have them anymore.

 

Yeah, for sure the mpg would be a lot better if you can make the engine breathe better by having headers and a bigger exhaust. I have so many extra performance mods from my CL just collecting dust in my garage which obviously won't work for the MDX. And I would do it all for the mpg, although this suv definitely gets out of It's own way for how heavy it is. I am also very surprised how well the AWD system works for a 15 yr old car. Before this I had an AWD manual Honda Element and I can say the MDX's AWD is 10x better. The AWD on the Element would only kick on at a VERY low speed. Either towing a boat up a slippery ramp or SLOWLY going through soft sand. If I gave it some throttle from a dead stop on a wet road the front tires would constantly keep spinning. The MDX on the other hand I can completely floor it from a dead stop on the slickest wet road and it just dead hooks all the time.

 

You would be amazed at SH-AWD as it adds performance, Not just all weather traction.

 

You can read what others are saying about MPG on all cars at:

fuelly dot com

 

So if I hollow out the cat it won't throw a code guys?

I'd love to get a MPG or 2 more outta my 06!

 

Mine doesn't have an O2 sensor after the catalytic converter so it didn't throw any codes, but not sure if the 06 model has an O2 sensor after the cat. Either way, I would still hollow it out, worst case scenario you get a O2 sensor spacer for it if it has one after the cat

 

Killer, thanks!

I'll do that '19 then.