Jetta Owners: Question About MPG - Fuelly Forums

Android Users - Coming Soon! - Migrating from aCar 4.8 to 5.0

Reply
 
Thread Tools Display Modes
 
Old 08-24-2011, 04:08 PM   #1
Junior Member
 
Join Date: Aug 2011
Posts: 1
Country: United States
Location: RVA
Jetta Owners: Question About MPG

I started tracking my MPG and the first thing I noticed was that most of the other Jettas on this site get between 30 and 40 mpg, while I get 20.

Any advice or insight? I have an 02 Jetta sedan with 115K on it. Just had the oil changed. I don't do partial fillups. I don't get cheap gas (like Wawa or Sheetz or Sam's Club/Kroger), I fill up at the BP where I work so the gas has the additive to clean the engine.

What do you do?
__________________

TaraDefies is offline   Reply With Quote
Old 08-24-2011, 04:14 PM   #2
Senior Member
 
Join Date: Jul 2008
Posts: 260
Country: United States
Location: McMinnville, OR
Most of the high-mileage Jettas are diesel powered on this site. My wife has one, and it's a nice small turbo diesel engine that really saves on gas and is hopped up enough at the factory to feel like a normal engine. They average 15+mpg more than the normal-in-the-US gas engines.

Here's a link to every other Jetta that is the same year as yours, with the diesel ones filtered out. 18-31mpg looks like the range for gas only engines.
__________________

mathowie is offline   Reply With Quote
Old 08-26-2011, 07:34 AM   #3
Junior Member
 
Join Date: Aug 2011
Posts: 1
Country: United States
You may need to check your O2 sensors. The O2 sensors may be faulty but not cause a code. They will also casue your car to use more gas. With 115k miles on your car. I would start looking there.
Hacky2447 is offline   Reply With Quote
Old 08-27-2011, 12:15 AM   #4
Registered Member
 
Join Date: May 2010
Posts: 70
Country: Canada
I agree with the 02 sensor. I scanned my coworkers saturn and his check engine light was coming on every once in a while and according to my scan guage II his code was still pending but he replaced the front 02 sensor and that took care of it.

You can always check your fluids, tire pressure, any unecessary weight in the car, handbrake staying on by accident when car drives, staying under 3000rpm will give you the best MPG.
__________________

2007 Toyota Matrix Base (SOLD)
MatrixDom is offline   Reply With Quote
Old 08-28-2011, 05:03 AM   #5
Junior Member
 
Join Date: Apr 2011
Posts: 1
Country: United States
Location: San Diego, CA
A couple other things to check are the Mass Airflow Sensor. If you get your car scanned and you see a pending P1128 or P1127, that could be indicative of a bad MAF.

The MAF is what monitors air/fuel mixture and the codes above are for a lean and rich condition. Both of these conditions could reduce your gas milage. I had a bad MAF, and it lowered my milage by about 2-3 MPG.

Something else you should check is the fuel filter. If it hasn't been changed recently (last couple of years) it may be clogging, which will reduce mileage as well.

Everything else mentioned above should also be checked.
Tkang69 is offline   Reply With Quote
Old 08-28-2011, 10:58 AM   #6
Out of Fuel
 
Join Date: Oct 2009
Posts: 216
Country: United States
Location: EUP Michigan
Actually if a fuel filter is clogged up, it will slow fuel delivery, actually causing an increased MPG. So will low fuel pressure in the case of a bad fuel pump. If you are burning less fuel (cause it isn't reaching the engine as well) you will get better MPG, but less performance. But this means you are running leaner, which could cause other long term problems if this condition continues for a period of time.

So leaner = less fuel = more mpg = engine runs hotter and can cause long term damage

VS

Richer = more fuel = less mpg = engine runs rough, stinky, idle issues, hard starting, etc.

Its always best to make sure your car is properly tuned up and operating at its peak efficiency.
DTMAce is offline   Reply With Quote
Old 09-07-2011, 11:09 AM   #7
Junior Member
 
Join Date: Aug 2009
Posts: 1
Country: United States
Tara,

one more thing to take into consideration is what most of your driving consists of: in-town versus highway.

Depending on the engine, your Jetta's consumption rating is anywhere between 17 - 21 mpg for city driving. If you have any of the 2.8 L engines (VR6), then you're actually doing better than the rating with 20 mpg. Even if you have the 1.8 L engine you're still pretty much on-par with the city rating (21). For an almost 10 yrs old car your Jetta actually is doing pretty decent.

Contrary, if your driving is mostly highway, then you need to have it checked out (scanned, etc).

As far as "most of the Jettas" on Fuelly with 40+ mpg, as people have said it before, those are diesel powered engined. However, don't compare yours with those, as if you read between the lines you'll notice that some people "get" 49 mpg with 85 % city driving...yeah, right...

Only compare your mpg against your own car's rating.
chefro is offline   Reply With Quote
Old 09-08-2011, 07:49 PM   #8
Junior Member
 
Join Date: Sep 2011
Posts: 1
Country: United States
Location: Sugar Hill GA
Just an FYI Kroger Gas stations have a contract for the next 4 years with BP gas. That's what is in their tanks.

Also Im not a Jetta owner but I know alot about cars. if you have the same engine profile as someone else getting 10 more MPG then you. Check the basics first Air Filter (ever 10,000 miles) Fuel Filter (Every 30,000 miles) Spark Plugs (every 100,000 if you buy platinum plugs). Then move on to O2 sensors if you have over 100,000 and the O2 sensors are original then they should be changed.
rcharrisoniv is offline   Reply With Quote
Old 09-08-2011, 09:10 PM   #9
Senior Member
 
Join Date: Mar 2011
Posts: 329
Country: United Kingdom
> if you have the same engine profile

I'd have thought that the journey profile was just as important as the engine. If somebody is doing 5 miles / day in stop-go city traffic they're going to have terrible MPG compared ot someone doing 80 miles/day at 60mph. But the trouble is that you generally don't know this from the site, so it is hard to compare like with like.
MMUK is offline   Reply With Quote
Old 09-09-2011, 03:43 AM   #10
Out of Fuel
 
Join Date: Oct 2009
Posts: 216
Country: United States
Location: EUP Michigan
Hence the city/highway percentages we now have... lol
__________________

DTMAce is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Powered by vBadvanced CMPS v3.2.3


All times are GMT -8. The time now is 11:32 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.