Throttle body bypass increase gas consumption?
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Throttle body bypass increase gas consumption?
Hi Guys,
*I did a throttle body bypass several years ago. *I used to get around 375 km per tank in the city, now I only get 250km. The change seemed the same time I did the mod.*I have a 1995 camaro z28. *I live in Vancouver bc Canada. *Outside temps in winter are between 35 and 50F but can go down to 15F...summer temps are between 60 and 85F...similar weather to Seattle.
I am wondering if the gas is not burning well enough because of the throttle body bypass and resulting in poorer gas mileage? With cooler temps the consumption seems to get worse...does this make sense?
*I did a throttle body bypass several years ago. *I used to get around 375 km per tank in the city, now I only get 250km. The change seemed the same time I did the mod.*I have a 1995 camaro z28. *I live in Vancouver bc Canada. *Outside temps in winter are between 35 and 50F but can go down to 15F...summer temps are between 60 and 85F...similar weather to Seattle.
I am wondering if the gas is not burning well enough because of the throttle body bypass and resulting in poorer gas mileage? With cooler temps the consumption seems to get worse...does this make sense?
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Joined: Jun 2005
Posts: 311
From: Sunny South Florida
Re: Throttle body bypass increase gas consumption?
Is the motor stock? The computer makes minor AFR changes to accomodate changes in ambient air temp, engine temp etc... I can't see how a T/B bypass can make a huge difference in fuel mileage but I've never really tracked fuel mileage on my Z. Also, what is the fuel mileage diff in MPG? MIght be easier for us to see if 375km to 250km is a big change. I was never good in math.......
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Joined: Nov 1998
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From: Hell was full so they sent me to NJ
Re: Throttle body bypass increase gas consumption?
You need to accurately measure fuel mileage in "miles per gallon" "Tank" is not a consitent measurement.
Your fuel mileage will drop when the weather is cold because the colder the engine is, the richer the PCM sets the cold start A/F ratio. It also elevates the cold start idle based on engine temp. You're going to be using more fuel until the engine warms up. If you drive primarilly short trips, the loss in mileage will be noticeable. Cold air also means more power. The denser air requires more fuel mass. If you have the habit of going WOT frequently, fuel mileage will drop more in cold weather. Then there's the increased use of oxidizers in cold weather, and they have less enrgy content and reduce fuel mileage.
I kept accurate records of fuel useage over the first 7 years of owning my Formula (1994-2001) and there was no significant loss of fuel mileage that could be attributed to the throttle body coolant bypass. GM put the coolant on the throttle body to prevent throttle body icing, due to the venturi effect, in cold climates. They didn't put it there to improve fuel mileage.
Your fuel mileage will drop when the weather is cold because the colder the engine is, the richer the PCM sets the cold start A/F ratio. It also elevates the cold start idle based on engine temp. You're going to be using more fuel until the engine warms up. If you drive primarilly short trips, the loss in mileage will be noticeable. Cold air also means more power. The denser air requires more fuel mass. If you have the habit of going WOT frequently, fuel mileage will drop more in cold weather. Then there's the increased use of oxidizers in cold weather, and they have less enrgy content and reduce fuel mileage.
I kept accurate records of fuel useage over the first 7 years of owning my Formula (1994-2001) and there was no significant loss of fuel mileage that could be attributed to the throttle body coolant bypass. GM put the coolant on the throttle body to prevent throttle body icing, due to the venturi effect, in cold climates. They didn't put it there to improve fuel mileage.
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