RuninRoach

This is what someone tried to tell me the other day and i decided to do the math on it (all figures rounded up).

1L of fuel = 1.8lbs
19 US Gallons = 57L

57L * 1.8lbs/L = 103lbs

now 103lbs is a lot so by doin half a tank you drop about 50lbs (not taking into account the reserve gallons).

How much of a difference would 50lbs make?

Well after doing all this silliness i discovered a great article in the....(cough)......Miata forum.....

salimshah

yes every bit of weight you lug impacts the mpg.

But other than the MPG spec, keep in mind the extra trips to the gas station will burn gas (not to mention your precious time).

As an extreme example ... no one would like to have a gas tank with 10 gal capacity to get better MPG.

Folks who have been on this forum for long would remember the first few complaints were about RX's crusing range. Later models got a bigger tank.

Salim

lexus114

I remember that.

rxovermdx

When you are cruising on neutral (coasting down hill or to a stop light), eatra weight will actually get you further due to the law of the momentum..(but oppisite is true in uphill or facing wind-resistance). I use N a lot..and I turn ignition off when I know that I have to wait more than 15 seconds on a light.

RuninRoach

doesn't that do a number on your transmission as well as starter?

lexus114

I dont think I will ever go to that extreme. For the little that is saved, it simply isnt worth the extra strain on the starter, plus I dont like to screw around with the trans like that. It doesn completely go into neutral believe it or not.

rxovermdx

Gently step on the brake then tap the lever into N, smooth as butter. I woudl imagine wear on tranny if you go crazy 1-2-3-D- and so forth.

Starting car extra few times a day vs. all that fuel you are burning and stress on your engine block and fuel injection system..take your pick which is cheaper in long-run..

rxovermdx

you will actually SAVE on your tranny since you are not using upon deceleration (less strain and less moving parts/friction/heat). HEAT is the worst enemy for the auto tranny. All you are doing is disengaging from the gear. You guys who are afraid haven't had experience with manual gears. I had 02' Camry auto and original tranny lasted me 145k miles and running strong until I sold it (it wasn't even electronically controlled).

rxovermdx

Yeah, I wouldn't recommend it for RX 330 since it is a weaker system, you might get screwed if you have crappy tranny to begin with.

lexus114

Allllllll Ritey then....

mandyfig

Future cars (maybe in a year or 2) will have start-stop capability on demand, just like you mentioned. But starters have to be re-designed and other components related to starting the vehicle. The duty rating shot up the roof and therefore reliability will have to catch up. More cost for the consumer.

The game is all about how to shut that engine down when not required, so it does not consume gas. Isn't that the game now?

Hence the Hybrid, ERV and the EV? NG vehicle (No gas) vehicle?

Who takes the hit....us!

All in the name of carbon footprint.

salimshah

coasting is illegal in many states ... readers should be careful .. remember "safety first"

As far as uphil/down-hill, we all come back to same spot at the end of the day.

Salim

lexus114

You are absolutely right about that. I didnt even think of that. I know for sure it`s illegal in a big truck.

rxovermdx

really, many more things are more illegal than cruising to a stop..certainly can't be worse than breaking speed limit which we all do (in the emergency situations

There is nothing worse for your engine than idling for a long-time while standing.. It kills me to see people idling at a train stop, bridge, etc., and complaining of low MPG?? Isn't Prius a good example of ultimate COASTER?

lexus114

cant compare the two. The Prius is a hybrid,and therefore designed to do this. ^^^