Newbie HELP! Mpg Sucks
Thread Starter
|
Junior Member
Joined: Nov 2008
Posts: 4
Newbie HELP! Mpg Sucks
I bought a used 2005 A4 Avant 1.8 in November that has 80k miles. There are a number of quirky and annoying things about it that may or may not be related and I'm looking for some advice. Here are some of the fun facts:
- My speedometer is 5 mph off when driving at highway speeds (checked against GPS)
- I can't get more than 300 miles on a tank of gas regarless of highway vs. country roads to work and I'm not a leadfoot.
- I got frustrated with the mileage soon after I bought it and had the 80k service performed where they changed the spark plugs and filters (except gas filter). No improvement.
- I inflated the tires (brand new Pirelli) to 35 lbs each and while there was improvement, I still can't get over 300 miles.
- My on-board computer says I'm averaging a little north of 25 mpg per tank but when I do manual calculations at the gas station I'm getting between 20 and 21. Seems like a pretty big gap.
It's frustrating because I bought a much smaller car (and a 4 cylinder at that) and am getting the EXACT same mileage I was getting with my Acura MDX.
I've already spent over $1,000 on it since I purchaed in November and if I'm going to do anymore I want to go to the dealership with a very targeted idea of what I need them to do. Any advice and insight would be greatly appreciate.
- My speedometer is 5 mph off when driving at highway speeds (checked against GPS)
- I can't get more than 300 miles on a tank of gas regarless of highway vs. country roads to work and I'm not a leadfoot.
- I got frustrated with the mileage soon after I bought it and had the 80k service performed where they changed the spark plugs and filters (except gas filter). No improvement.
- I inflated the tires (brand new Pirelli) to 35 lbs each and while there was improvement, I still can't get over 300 miles.
- My on-board computer says I'm averaging a little north of 25 mpg per tank but when I do manual calculations at the gas station I'm getting between 20 and 21. Seems like a pretty big gap.
It's frustrating because I bought a much smaller car (and a 4 cylinder at that) and am getting the EXACT same mileage I was getting with my Acura MDX.
I've already spent over $1,000 on it since I purchaed in November and if I'm going to do anymore I want to go to the dealership with a very targeted idea of what I need them to do. Any advice and insight would be greatly appreciate.
1st Gear
Joined: Mar 2008
Posts: 50
From:
Hi,
I have an 05 1.8L quattro. To respond to your issues...
- My speedometer is 5 mph off when driving at highway speeds (checked against GPS)
True. its about 4-5mph off at 70mph--more when you are going faster- i.e. the error is a percentage of your actual speed. Some error is expected in most analog speedos ...i just live with it! So if I'm foing 75 according to the speedo, its actually only 70mph!
- I can't get more than 300 miles on a tank of gas regarless of highway vs. country roads to work and I'm not a leadfoot.
- I got frustrated with the mileage soon after I bought it and had the 80k service performed where they changed the spark plugs and filters (except gas filter). No improvement.
- I inflated the tires (brand new Pirelli) to 35 lbs each and while there was improvement, I still can't get over 300 miles.
- My on-board computer says I'm averaging a little north of 25 mpg per tank but when I do manual calculations at the gas station I'm getting between 20 and 21. Seems like a pretty big gap.
couple of things- are you using premium? If not you mileage will suffer. Also, mileage is lower in winter months due to a combination of the time it takes for the engine to get to a decent operating temp. and the fact that oil companies use a slightly different "blend" of gasoline in winter.
My car has given me up to 37mpg on the highway in summer but it is noticeably lower in the winter.
I have an 05 1.8L quattro. To respond to your issues...
- My speedometer is 5 mph off when driving at highway speeds (checked against GPS)
True. its about 4-5mph off at 70mph--more when you are going faster- i.e. the error is a percentage of your actual speed. Some error is expected in most analog speedos ...i just live with it! So if I'm foing 75 according to the speedo, its actually only 70mph!
- I can't get more than 300 miles on a tank of gas regarless of highway vs. country roads to work and I'm not a leadfoot.
- I got frustrated with the mileage soon after I bought it and had the 80k service performed where they changed the spark plugs and filters (except gas filter). No improvement.
- I inflated the tires (brand new Pirelli) to 35 lbs each and while there was improvement, I still can't get over 300 miles.
- My on-board computer says I'm averaging a little north of 25 mpg per tank but when I do manual calculations at the gas station I'm getting between 20 and 21. Seems like a pretty big gap.
couple of things- are you using premium? If not you mileage will suffer. Also, mileage is lower in winter months due to a combination of the time it takes for the engine to get to a decent operating temp. and the fact that oil companies use a slightly different "blend" of gasoline in winter.
My car has given me up to 37mpg on the highway in summer but it is noticeably lower in the winter.
1st Gear
Joined: Jul 2008
Posts: 33
Hey your speedometer might need to be recalibrated. You probably just might be getting over 300 miles / tank but if the speedometer is not calibrated then the Instant and Average fuel mileage will be off. So if the speedometer is off it is possible you are getting lower than average fuel mileage readings. Speedometer calibration is easy. First thing, ensure the correct size tires are installed in the car and that the tires are inflated to the reccomended pressure. Then take it to the dealer so they can hook it up to the computer and adjust the speedometer. You should notice that at 70mph you really only should be 1-2 mph off. My Audi A4 is only 1 mph off at 90mph. It reads 89mph.
Senior Member
Joined: May 2006
Posts: 491
From:
Keep in mind you have an Avant, which is heavier than the sedan so don't expect to get the same as them. Aside from removing extra weight that might be in the trunk, tire pressure, spark plugs, oil and filter there other things you can try.
First, you use more gas when in boost (more air from turbo = more gas to mix with it) so if you're manual, shift before boost hits.
Check and make sure your air intake isn't clogged. It's more than just the air filter, there might be a catch in the snorkel part that can get clogged. I found cigarette butts and leaves packed in there once. I also replaced my filter with a K&N drop in, which some say the oil in it causes issues with the MAF but after 30k it hasn't for me (though you have to use oil sparingly at cleaning).
Fuel filter is certainly a possibility after 80k. Audi doesn't change that and instead waits for the fuel pump to die. The part is $40 or so and it's an easy DIY that helped me with my mpg.
You might want to try the seafoam DIY to help clear out injectors and such.
How long do you let the car warm up? If it's a long time, don't. I am pretty sure the manual says you can start it up and go.
As mentioned above, winter is a tough time to do mpg since the gas is a poorer blend and colder temps affect your engine. So have some patience until the summer mix comes back.
I used regular once by accident but my mpg was the same. either way, I always go 93 octane. Gas with ethanol doesn't help, either.
Other than the above: alignment can cause bad mpg and you need to get it done properly since it's AWD, O2 sensor and MAF may be going so you can DIY change the former and DIY clean the latter, timing belt might have added drag from the aged components and probably should be done now rather than at 100k because of issues with the plastic water pump.
That's all I can think of now. Either way, the dealer will gladly do what you ask and charge you for it. Roll up your sleeves, buy what you want to try from places like ECS, genuineaudiparts, or whoever and give it a try. The beauty of these cars is there is tons of information out there to reference and use to save yourself money.
First, you use more gas when in boost (more air from turbo = more gas to mix with it) so if you're manual, shift before boost hits.
Check and make sure your air intake isn't clogged. It's more than just the air filter, there might be a catch in the snorkel part that can get clogged. I found cigarette butts and leaves packed in there once. I also replaced my filter with a K&N drop in, which some say the oil in it causes issues with the MAF but after 30k it hasn't for me (though you have to use oil sparingly at cleaning).
Fuel filter is certainly a possibility after 80k. Audi doesn't change that and instead waits for the fuel pump to die. The part is $40 or so and it's an easy DIY that helped me with my mpg.
You might want to try the seafoam DIY to help clear out injectors and such.
How long do you let the car warm up? If it's a long time, don't. I am pretty sure the manual says you can start it up and go.
As mentioned above, winter is a tough time to do mpg since the gas is a poorer blend and colder temps affect your engine. So have some patience until the summer mix comes back.
I used regular once by accident but my mpg was the same. either way, I always go 93 octane. Gas with ethanol doesn't help, either.
Other than the above: alignment can cause bad mpg and you need to get it done properly since it's AWD, O2 sensor and MAF may be going so you can DIY change the former and DIY clean the latter, timing belt might have added drag from the aged components and probably should be done now rather than at 100k because of issues with the plastic water pump.
That's all I can think of now. Either way, the dealer will gladly do what you ask and charge you for it. Roll up your sleeves, buy what you want to try from places like ECS, genuineaudiparts, or whoever and give it a try. The beauty of these cars is there is tons of information out there to reference and use to save yourself money.
Last edited by wolfdog; Feb 27, 2009 at 03:19 PM.
Thread Starter
|
Junior Member
Joined: Nov 2008
Posts: 4
Thanks for the reply guys, I am using premium but I am not sure if the previous owners had and whether or not that would make a difference over time. I live in Michigan and we've had a pretty cold winter so I that may very well be a contributing factor. Just another reason I can't wait for spring to arrive.
I'm probably less concerned about the speedometer calibration - I've done the same self-adjustment in my head when I'm on the highway. I was just wondering with mileage that low if there could be anything else like the fuel injectors needing to be cleaned or something like that. Again, thanks for the replies.
I'm probably less concerned about the speedometer calibration - I've done the same self-adjustment in my head when I'm on the highway. I was just wondering with mileage that low if there could be anything else like the fuel injectors needing to be cleaned or something like that. Again, thanks for the replies.
Thread Starter
|
Junior Member
Joined: Nov 2008
Posts: 4
Thanks Wolfdog, I really appreciate all of the advice and will take a crack at DIY your suggestions. I've dropped enough $ with the dealer...
Keep in mind you have an Avant, which is heavier than the sedan so don't expect to get the same as them. Aside from removing extra weight that might be in the trunk, tire pressure, spark plugs, oil and filter there other things you can try.
First, you use more gas when in boost (more air from turbo = more gas to mix with it) so if you're manual, shift before boost hits.
Check and make sure your air intake isn't clogged. It's more than just the air filter, there might be a catch in the snorkel part that can get clogged. I found cigarette butts and leaves packed in there once. I also replaced my filter with a K&N drop in, which some say the oil in it causes issues with the MAF but after 30k it hasn't for me (though you have to use oil sparingly at cleaning).
Fuel filter is certainly a possibility after 80k. Audi doesn't change that and instead waits for the fuel pump to die. The part is $40 or so and it's an easy DIY that helped me with my mpg.
You might want to try the seafoam DIY to help clear out injectors and such.
How long do you let the car warm up? If it's a long time, don't. I am pretty sure the manual says you can start it up and go.
As mentioned above, winter is a tough time to do mpg since the gas is a poorer blend and colder temps affect your engine. So have some patience until the summer mix comes back.
I used regular once by accident but my mpg was the same. either way, I always go 93 octane. Gas with ethanol doesn't help, either.
Other than the above: alignment can cause bad mpg and you need to get it done properly since it's AWD, O2 sensor and MAF may be going so you can DIY change the former and DIY clean the latter, timing belt might have added drag from the aged components and probably should be done now rather than at 100k because of issues with the plastic water pump.
That's all I can think of now. Either way, the dealer will gladly do what you ask and charge you for it. Roll up your sleeves, buy what you want to try from places like ECS, genuineaudiparts, or whoever and give it a try. The beauty of these cars is there is tons of information out there to reference and use to save yourself money.
First, you use more gas when in boost (more air from turbo = more gas to mix with it) so if you're manual, shift before boost hits.
Check and make sure your air intake isn't clogged. It's more than just the air filter, there might be a catch in the snorkel part that can get clogged. I found cigarette butts and leaves packed in there once. I also replaced my filter with a K&N drop in, which some say the oil in it causes issues with the MAF but after 30k it hasn't for me (though you have to use oil sparingly at cleaning).
Fuel filter is certainly a possibility after 80k. Audi doesn't change that and instead waits for the fuel pump to die. The part is $40 or so and it's an easy DIY that helped me with my mpg.
You might want to try the seafoam DIY to help clear out injectors and such.
How long do you let the car warm up? If it's a long time, don't. I am pretty sure the manual says you can start it up and go.
As mentioned above, winter is a tough time to do mpg since the gas is a poorer blend and colder temps affect your engine. So have some patience until the summer mix comes back.
I used regular once by accident but my mpg was the same. either way, I always go 93 octane. Gas with ethanol doesn't help, either.
Other than the above: alignment can cause bad mpg and you need to get it done properly since it's AWD, O2 sensor and MAF may be going so you can DIY change the former and DIY clean the latter, timing belt might have added drag from the aged components and probably should be done now rather than at 100k because of issues with the plastic water pump.
That's all I can think of now. Either way, the dealer will gladly do what you ask and charge you for it. Roll up your sleeves, buy what you want to try from places like ECS, genuineaudiparts, or whoever and give it a try. The beauty of these cars is there is tons of information out there to reference and use to save yourself money.
Thread
Thread Starter
Forum
Replies
Last Post
