electricview

I was just curious, does anyone know how the 14+ mdx's get the SAME gas mileage as the smaller lighter 13+ rdx's? I understand they use the same engines, but the MDX has higher HP which makes me think it should use a bit more gas, not to mention it still has SHAWD and is presumably heavier, but it gets the EXACT same gas mileage as the smaller/lighter RDX? That seems off to me.. or is it that the MDX's engine is tuned a little tighter? Maybe it must have premium fuel where as our RDX's can run on slightly less than premium?

Infamous425

different engine. New MDX uses the "earth dreams" direct injection engine while the RDX uses the old 3.5

sv_ted

Also, EPA estimates are not reality. They are made for a fixed route that may not resemble your driving. And the route is simulated; not actually driven. And the data is taken by the auto manufacturer; not the EPA. I doubt that the MDX gets the same mileage as the RDX in the real world.

mrgold35

I think you might need to look at it opposite. The MDX gets the same mpgs as the smaller lighter RDX because of its engine improvements. You also get more room, higher tow rating, more hp/tq, improved awd, updated tech, and additional safety features with no mpg penalty.

I drove back from my in-laws 240 miles last weekend with a stiff +20 mph headwind all the way. It showed 13.8 mpg on M.I.D. when I got to town on my 300HP, non-VCM, +4600lb (5500lbs with 4 folks/gear), 11 MDX. The only thing that eased the pain was gas was $2.29 for 91 at Sam's compared to $3.89 at the end of Aug/14.

justnspace

iTrader: (1)

Earth Dreams, Baby!

direct injection is a gift from the car gods

electricview

Wait, I thought the RDX had earth dreams ? the 2nd revision?

dawudih

Nope. No DI & lower compression. I think it's the 35J in the RDX & 35JY engine in the MDX.

loulinjai

Earth dreams is just a label for increased output and efficiency, it doesn't necessarily correlate with a specific technology in an engine.

For example the 13+ Accord V6 motor is branded as an earth dreams engine but it does not have direct injection. If you look at the technical details, the 13-15 RDX has a very similiar engine to the 13+ Accords but it is not branded as earth dreams.

There's a high probability the RDX will get a revised motor for MY2016 and possibly a new transmission for better fuel economy.

electricview

is this why its reported that the RDX can handle unleaded fuel better than some of the other acura cars? (TL, possibly newer MDX?) as acura only recommends premium....

mrgold35

I think Acura lowered the compression of the 3.5L and lowered the hp/tq to create a (imagined) difference between the RDX and MDX models. The RDX can handle lower octane fuels better because of the lower compression rate. The RDX compression level is probably the same as other Honda 3.5L V-6 engines. Even if they do add the exact same MDX engine for the RDX MMC, they will find some way to de-tune the RDX or have to add more HP for the MDX.

electricview

Hey Infamous you're in Kirkland? Sweeet I live right off the 160th exit in north Kirkland (they call us bothell now).. small world!


GO HAWKS!

hrothgar02

I can answer this question. We have a 2014 MDX and a 2014 RDX (FWD). Real world MPG: 1. MDX 19-20 mixed city driving (25+ on long highway trips)
2. RDX 22-24 mixed city driving (26+ on long highway trips)

The bottom line is that the MDX is 700lbs + heavier than the RDX. I believe the DI closes the MPG gap on the highway.

pittdoc

the mdx also has sh-awd, which the rdx does not

Acura has to bring the sh awa back in the rdx, it is such a differential feature to sell...its amazing in the snow and to handle in general