# Gas Mileage Questions

**URL:** <https://forums.speedlife.net/t/gas-mileage-questions/15836>\
**Category:** NYSpeed Automotive\
**Created:** [August 11, 2006, 1:28pm UTC](https://forums.speedlife.net/t/gas-mileage-questions/15836 "2006-08-11T13:28:15Z")\
**Posts on this page:** 1\
**Showing post:** 13

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**Author:** ![HotRodKid](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/hotrodkid/32/7609_2.png) [@HotRodKid](https://forums.speedlife.net/u/HotRodKid)\
**Post date:** [October 23, 2006, 8:40am UTC](https://forums.speedlife.net/t/gas-mileage-questions/15836/13 "2006-10-23T08:40:20Z")

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> [@Bigairskier1580](#):
>
> Downhill coast in gear FTW.
> 
> Watch o2 sensor voltage readings. Down hill, they will read 0 volts if you are in gear (any gear, regardless of engine speed). Coast down the same hill in neutral, and you will get voltage readings as the car will be burning fuel to keep running.

depends on how fast the car kicks over to the fuel cut …

the only way coasting in gear saves you fuel is if the cars EEC immediatly shuts off ALL fuel flow. for example, the EEC in the turbo sho does so … BUT only after a good 30 seconds of coasting in gear … and thats 30 seconds that fuels being dumped into the motor and not creating any accelation … thats a waste of fuel

engines use a certian amount of fuel / cylinder to maintain 14.7: 1, so @ 3000 rpm your ingesting more fuel then @ 800rpm … ALWAYS

good fuel economy comes from only using gas to accelerate as much as needed, when needed… burning fuel to slow down is as good an idea as using your brakes to accelerate :bloated:

or another way to think of this

does PEDALING down hill on a bike use less energy then taking your feet of the pedals ?

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