Bad gas mileage?
#1
12 Second Club
Thread Starter
iTrader: (1)
Join Date: Jan 2006
Location: Lafayette/West Lafayette, IN
Posts: 1,090
Likes: 0
Received 0 Likes
on
0 Posts
Bad gas mileage?
Ok, my truck is a '00 Z71 that is approaching 100k miles now.
I got it last year with somewhere in the low 90's for mileage (got from my dad... I've been driving it since I was 16). When I first got it it wasn't getting very good gas mileage... like 12 or 13 average (some highway, some in town). I did all the maintenance on it like spark plugs, filters, oil, and seafoamed it. Well, it then jumped up to over 15mpg instantly and did that for quite a while.
Now for some reason it's back down to 12.xx average every time... I went from getting like 250 mi. per tank, to over 300 (close to 350 sometimes), and now I'm back down to 250-ish (barely going to make it this tank). Now, I know it isn't the type of driving that i do, because that is about 90% on the exact same path back and forth to home from school and back on weekends.... so that isn't it. I'm definitely not driving more aggressively.... And I don't see why a couple thousand miles on anything should be able to take away over 3mpg like that...
So I don't really even know what to check (it's not tire pressure either . lol)... Any ideas? What could it be?
Thanks for any help.
I got it last year with somewhere in the low 90's for mileage (got from my dad... I've been driving it since I was 16). When I first got it it wasn't getting very good gas mileage... like 12 or 13 average (some highway, some in town). I did all the maintenance on it like spark plugs, filters, oil, and seafoamed it. Well, it then jumped up to over 15mpg instantly and did that for quite a while.
Now for some reason it's back down to 12.xx average every time... I went from getting like 250 mi. per tank, to over 300 (close to 350 sometimes), and now I'm back down to 250-ish (barely going to make it this tank). Now, I know it isn't the type of driving that i do, because that is about 90% on the exact same path back and forth to home from school and back on weekends.... so that isn't it. I'm definitely not driving more aggressively.... And I don't see why a couple thousand miles on anything should be able to take away over 3mpg like that...
So I don't really even know what to check (it's not tire pressure either . lol)... Any ideas? What could it be?
Thanks for any help.
#2
TECH Fanatic
Join Date: Jul 2005
Location: Beebe, Arkansas
Posts: 1,676
Likes: 0
Received 0 Likes
on
0 Posts
Ok, my truck is a '00 Z71 that is approaching 100k miles now.
I got it last year with somewhere in the low 90's for mileage (got from my dad... I've been driving it since I was 16). When I first got it it wasn't getting very good gas mileage... like 12 or 13 average (some highway, some in town). I did all the maintenance on it like spark plugs, filters, oil, and seafoamed it. Well, it then jumped up to over 15mpg instantly and did that for quite a while.
Now for some reason it's back down to 12.xx average every time... I went from getting like 250 mi. per tank, to over 300 (close to 350 sometimes), and now I'm back down to 250-ish (barely going to make it this tank). Now, I know it isn't the type of driving that i do, because that is about 90% on the exact same path back and forth to home from school and back on weekends.... so that isn't it. I'm definitely not driving more aggressively.... And I don't see why a couple thousand miles on anything should be able to take away over 3mpg like that...
So I don't really even know what to check (it's not tire pressure either . lol)... Any ideas? What could it be?
Thanks for any help.
I got it last year with somewhere in the low 90's for mileage (got from my dad... I've been driving it since I was 16). When I first got it it wasn't getting very good gas mileage... like 12 or 13 average (some highway, some in town). I did all the maintenance on it like spark plugs, filters, oil, and seafoamed it. Well, it then jumped up to over 15mpg instantly and did that for quite a while.
Now for some reason it's back down to 12.xx average every time... I went from getting like 250 mi. per tank, to over 300 (close to 350 sometimes), and now I'm back down to 250-ish (barely going to make it this tank). Now, I know it isn't the type of driving that i do, because that is about 90% on the exact same path back and forth to home from school and back on weekends.... so that isn't it. I'm definitely not driving more aggressively.... And I don't see why a couple thousand miles on anything should be able to take away over 3mpg like that...
So I don't really even know what to check (it's not tire pressure either . lol)... Any ideas? What could it be?
Thanks for any help.
Front O2 sensors maybe? They do ware out and your at 100k mile.
#7
12 Second Club
Thread Starter
iTrader: (1)
Join Date: Jan 2006
Location: Lafayette/West Lafayette, IN
Posts: 1,090
Likes: 0
Received 0 Likes
on
0 Posts
Really? I have no idea. I'm in lafayette, IN.
One thing I was thinking is that I think my thermostat is stuck open too, so that would only amplify the effect of it getting colder and taking longer to warm up.... what do you think? Would that do it?
One thing I was thinking is that I think my thermostat is stuck open too, so that would only amplify the effect of it getting colder and taking longer to warm up.... what do you think? Would that do it?
Trending Topics
#9
12 Second Club
Thread Starter
iTrader: (1)
Join Date: Jan 2006
Location: Lafayette/West Lafayette, IN
Posts: 1,090
Likes: 0
Received 0 Likes
on
0 Posts
Another thing I thought of to multiply the effect of the cold, along with the stuck thermostat, is the torque converter doesn't lock forever because it's cold. It took well over 5 miles on the highway for it to lock up the other day. I drove about 10 minutes, with most going 65 before it locked up in 16 degree weather.