# Am I saving gas? **URL:** \ **Category:** General Discussion\ **Tags:** s70, volvo\ **Created:** [March 26, 2011, 7:02pm UTC](https://community.cartalk.com/t/am-i-saving-gas/63026 "2011-03-26T19:02:34Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![FredC1953](https://avatars.discourse-cdn.com/v4/letter/f/2bfe46/32.png) [@FredC1953](https://community.cartalk.com/u/FredC1953)\ **Post date:** [March 26, 2011, 7:02pm UTC](https://community.cartalk.com/t/am-i-saving-gas/63026/1 "2011-03-26T19:02:34Z")
All 3 of our cars have automatic transmissions and tachometers. When traveling (say) 55 mph and I see a light turn red up ahead I immediately take my foot off the gas and start to coast. I notice that the rpm’s continue to hover around 2000 even tho’ my foots off the gas. Am I using the same amount of gas decelerating at 2000 rpms as when maintaining speed at 2000 rpms? ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [March 26, 2011, 7:26pm UTC](https://community.cartalk.com/t/am-i-saving-gas/63026/2 "2011-03-26T19:26:30Z")
You’re saving gas. Many cars shut of the fuel in the coasting situation you describe. ---
**Author:** ![euryale1](https://avatars.discourse-cdn.com/v4/letter/e/41988e/32.png) [@euryale1](https://community.cartalk.com/u/euryale1)\ **Post date:** [March 26, 2011, 7:29pm UTC](https://community.cartalk.com/t/am-i-saving-gas/63026/3 "2011-03-26T19:29:30Z")
No, You closed the throttle to minimum air which reduces the fuel use. The engine is often “locked” in overdrive until your speed drops below 35. Then normal down shifts will drop you to idle speed as you come to a stop. ---
**Author:** ![doubleclutch](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/doubleclutch/32/1281_2.png) [@doubleclutch](https://community.cartalk.com/u/doubleclutch)\ **Post date:** [March 26, 2011, 7:31pm UTC](https://community.cartalk.com/t/am-i-saving-gas/63026/4 "2011-03-26T19:31:23Z")
When the car is pulling the engine at an above idle speed with your foot off the throttle, modern cars shut the fuel off, so you are using no gas at all until the engine drops to a speed at which the injectors start firing again. I’m glad you asked! A lot of people write in with boneheaded “hypermiling” schemes like coasting in neutral or with the engine shut off, both of which are bad ideas. ---
**Author:** ![pleasedodgevan2](https://avatars.discourse-cdn.com/v4/letter/p/ad7895/32.png) [@pleasedodgevan2](https://community.cartalk.com/u/pleasedodgevan2)\ **Post date:** [March 26, 2011, 7:40pm UTC](https://community.cartalk.com/t/am-i-saving-gas/63026/5 "2011-03-26T19:40:17Z")
One of the best ways to economize is to get off the gas when closing on a stop situation. Yes, get that last eighth of a mile cheaply. ---
**Author:** ![mcparadise](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mcparadise/32/32_2.png) [@mcparadise](https://community.cartalk.com/u/mcparadise)\ **Post date:** [March 26, 2011, 8:39pm UTC](https://community.cartalk.com/t/am-i-saving-gas/63026/6 "2011-03-26T20:39:34Z")
You are doing the right thing. The throttle is closed regardless of engine speed. Most modern cars shut off the fuel injectors when coasting, so you’re using ZERO gas. ---
**Author:** ![jtsanders](https://avatars.discourse-cdn.com/v4/letter/j/c2a13f/32.png) [@jtsanders](https://community.cartalk.com/u/jtsanders)\ **Post date:** [March 27, 2011, 7:40pm UTC](https://community.cartalk.com/t/am-i-saving-gas/63026/7 "2011-03-27T19:40:32Z")
If you do this far enough in advance, you can coast through the cycle time on the light. If you don’t have to stop, you don’t have as much speed to gain when you pass through the light. That saves fuel, too. ---
**Author:** ![FredC1953](https://avatars.discourse-cdn.com/v4/letter/f/2bfe46/32.png) [@FredC1953](https://community.cartalk.com/u/FredC1953)\ **Post date:** [March 27, 2011, 8:38pm UTC](https://community.cartalk.com/t/am-i-saving-gas/63026/8 "2011-03-27T20:38:55Z")
Thank you! Good to know.