Accent coasts poorly, but why?

[GasSavers_maximilian]

My 2008 Hyundai Accent coasts much more poorly in neutral (it's a manual) than any other car I've owned. I was hoping it would improve after being broken in, but it persists. I live in a mountainous area, so I coast in neutral a lot and sometimes for quite extended periods (I live right on a big ridge). I asked my mechanic but he had no real suggestions as to why the coasting performance is so poor. Anyone have any ideas? I doubt it's something I can do much about, but a man can dream... Thanks.

[GasSavers_Erik]

How about jacking up each wheel and spinning it- to check if any of the brakes are dragging.

You could try to make a belly pan to improve aero- is that rear bumper cover hollow underneath? If so, it could create a parachute effect if it is scooping up air all of the time.

[GasSavers_maximilian]

Excellent practical suggestions! The rear bumper is indeed hollow and partially exposed to form somewhat of a scoop. Maybe some sheet metal to cover that up? But how to attach it. Have to think.

Need to wait on warmer weather to spin each wheel. Still a ton of snow here in VT!

I know my snow tires coast worse than my all-weathers, but even accounting for that it still coasts badly.

[vxdude]

the tire pressure is at its max, right?

[GasSavers_maximilian]

Yes, they are. My snow tires only have a max of 35, but the all weathers I run in the summer are more than that (the value escapes me at the moment). My previous vehicle (a Honda Accord) coasted significantly better even with winter tires inflated only to 32 psi. And it was a 1990 with 150,000 miles! Rust killed it in the end.

[theholycow]

Google tells me the aerodynamic drag coefficient for that car is a respectable .31, so that's probably not the problem. At 2500 pounds it shouldn't be too light to coast reasonably with that drag coefficient.

Check the wheels for free spinning as mentioned above, not only looking for dragging brakes but also a bad wheel bearing.

Maybe there's lots of friction in the drivetrain? Thick fluid in the transmission and differential, or badly designed CV joints? That would seem to be a stretch.

[GasSavers_maximilian]

I have been trying to figure out in general why the Accent's mpg is only 32. That's worse than the Aveo and the Yaris. I notice that the automatic transmission Accent is actually rated higher than the manual one for highway driving.

[R.I.D.E.]

Use the lightest weight gear lube recommended.

regards
gary

[GasSavers_maximilian]

Originally Posted by R.I.D.E.

Use the lightest weight gear lube recommended.

Well that's cheap and easy to try. Cool.

[GasSavers_Pete]

Have a look at the handbrake (emergency brake) adjustment as well.
Sometimes they can not release fully and cause a significant amount of drag.
Easiest way is to put your finger on the hub or as close as you can get to it and feel if it is at all hot after a long coast.

Good luck , Pete.