Sentra grille block?

[klrv6]

So I have semi-retired our Suburban for now This is now my daily driver.

What is the forums opinion of covering up the massive opening in the lower portion of the grille? I am shooting for 45mpg and currently get 39-41 on my drives to and from work. I also plan on removing the antenna and making air deflectors for each wheel.

[FastPlastic]

Go for it That opening seems a little excessive anyway.

[azraelswrd]

Couldn't hurt but test first to see if its safe/effective for the car. Do you have a way to monitor instant MPG with the Sentra? That might get you your goal (or at least closer to it). If you drive mostly city, focus on weight and tires. If the highway, aero should be a priority (though all areas should be addressed).

[Arminius]

I agree with everything azraelswrd said. Also, you might be better off covering the top grill than the bottom if your engine has trouble keeping cool. I lived near Lexington for 3 years, so I know it gets hot there. Is your Sentra an automatic or a manual?

[lunarhighway]

i'd go for a top grill block first as well, all air entereing there will have a tougher time getting out of the engine bay again the bottom grill is closer to the bottom of the car.
also it will make for a smoother transition to the hood.

if you can get away with a full top grillblock you car start blocking parts of the lower grill.

in any case i'd make provisions for quick removal of the block, or a movable door, in case temperatures go up.

grillblocks are nice, but do some testing, also take into account that for short trips (wich might make up your dayly commute) more grill blocking will be allowed, but for longer trips you might need to remove some.

wheeldams seem to be a good thing.

[klrv6]

It is a manual so I don't have to worry about extra heat from the tranny cooler. Scangauge 2.0 in hand and read 40.9 @ 75mph on my 113 mile trip this morning. I know at highway speeds that opening is way too large. The blocks I create will be able to be removed in less than a minute.

[NeilBlanchard]

Hi,

I would cover the upper grill (and the recesses where the foglights would go), and if that goes well, I would cover the outer sections of the lower grill.

[klrv6]

And deflectors in front of all the tires?

[azraelswrd]

Deflectors/fairings/dams in front and behind the wheels wouldn't hurt either (just be careful of ground clearance on the route you use). A partial belly pan to clean up and smooth out the under-turbulence will also help and rear wheel skirts for even more aero improvement.

[lunarhighway]

deflectors are a tricky matter once you get into them. they're easy enough to make, but how large they need to be depends on the particular layout of your car.

from what i've observed on production cars, is that appart from shielding part of the tire they're also used to keep air out of the wheelwell behind the tire. due to steering clearence of the front tire this can be quite a big gap. also suspention links often project from below the lowest part of the stock airdam/bumper/bellypan

what i find very usefull is to look underneath the car at this level and see what sticks out. have a good look at production setups and try to figure out why they look the way they do.
a casual stroll trough a parking lot will be helpfull and unless you get down on all four's to look underneath cars noone will notice... and even than... if you vaguely know people with an interesting car, i'm sure they'll let you have a more upclose look if you express your intrest