Retro aeromods: Datsun 240Z factory bolt-on "G-nose" good for +5.5% mpg and +5 mph - Fuel Economy, Hypermiling, EcoModding News and Forum

MetroMPG · 02-15-2009, 07:38 PM

Base / stock Z-car nose vs. "G-nose" version:

Car & Driver, May 1974:

Quote:

Datsun, at least in Japan, has some equally impressive parts that it doesn’t widely advertise. Fortunately, car enthusiasts in the homeland can buy a version of the Z-car known as the 240ZG (260ZG for 1974).

...

From an aerodynamic point of view, the G-nose is a gold mine. It includes all the parts necessary to reshape the Z-car’s front end from the lower edge of the hood forward. The new panels bolt on in about two hours adding 4.8 inches to the overall length of a ‘73 car and 7.3 inches to pre-bumper era ’72 or earlier cars.

The G-nose reduces drag because of the extra length - it’s that much closer to a bullet shape - and also due to the fact that the grille opening is much tighter and the headlamp openings are sealed.

At 70 mph the gain in fuel economy (is) 1.2 mpg.

And there are other side benefits. The top speed on Ontario’s straight is up from 115 mph with the stock 240Z to 120 with the G-nose. And front end lift is less than stock by 95 pounds at 70 mph.

Unfortunately, the G-nose doesn’t come cheap. The complete package is available... for $635 with headlamp covers, or $475 without.

Note: the 5.5% fuel economy improvement cited in the thread title is my calc, based on C&D's measurement of the stock/base 240Z of 22 mpg (US) at 70 mph.

Frank Lee · 02-15-2009, 07:58 PM

Quote:

The G-nose reduces drag because of the extra length

I don't think so.

You'd think those bulky fender flares would slow it back down again.

MetroMPG · 02-15-2009, 08:02 PM

And the wider tires they stuck under them.

Actually, that isn't the actual car C&D used - I doubt they added the flares on theirs for the test.

I thought this might stir things up a bit.

I agree: it's not the extra length itself, but what they did with the extra length. They could have produced the same shape in the same overall length if they really wanted to (ie. designed in from the start, not as a bolt-on addition).

cfg83 · 02-15-2009, 08:02 PM

MetroMPG -

That's very cool. I keep thinking that the nose is less important than the rear of the car, but a 5+% improvement is nothing to laugh at.

The "look" reminds me of the original Miami Vice car, the Ferrari Daytona.

CarloSW2

MetroMPG · 02-15-2009, 08:07 PM

Keep in mind, it's not just the nose. They reduced the grille opening, covered the headlight buckets and cleaned up the brutal leading edge of the hood. Also probably lowered the stagnation point.

It's easy to get a 5.5% improvement when your starting point is a face like that!

And, yeah, I thought it looked like that Ferarri too. Ferris Bueller's.