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My 2003 VW New Beetle

Have had alot of issues with this year/model and trying to work out all the bugs. Have been successful for the most part (after some expense) but my mechanic and I are stumped about the poor gas mileage–Any ideas?? Your help would be much appreciated–Thanks in advance

I’m not sure what you’re asking for here. Sorry.

“Lots of issues” and VW New Beetle goes together like toast and jam.

" . . . trying to work out all the “bugs.” That’s a good one! Beetle, bugs; I get it.

“Poor gas mileage.” Wow, that really nails it down.

Define “poor gas mileage.” Please.

You didn’t give us any numbers to work with, nor did you tell us how you arrived at the numbers you use to determine you’re getting “poor gas mileage.”

Some people define poor gas mileage as anything under 35 mpg. Others think 25 mpg is wonderful mileage. Still others are happy with 15 mpg. It all depends on what you’re driving, and how and where you’re driving it.

You got some “splainin” to do, Reva.

Please give us more information so maybe we can fit the pieces of this puzzle together and maybe provide some help to you.

I would start with the MAF. Does it have any stored error codes?

Not knowing what the prior issues are, hampers possible responses. Often apparently different issues are related.

LOL you’re right!! It’s sort of hard to “'splain” without sounding like I’m “whining” but the first indication it was 'under performing" was a year or more back. The indicator light and sound that I need to fill up would respond at (seriously every tank) at 327 miles. It was the same as a beetle I owned previously and was impressed they were that precise. When I started having issues with it, the indicator would sound at any where between 250 and 310. Im guessing that my mileage has dropped or ‘wasted’ so to speak about 1 or two gallons of gas per tank as compared to when I first bought the vehicle. I know thats not giving you direct figures but hope that gives you a better idea. Thanks for your help and expertise–:slight_smile:
PS I do both town and road driving. The type/style of driving I do has not changed since purchasing the vehicle.

If the car drives well at this point, I would concentrate on the MAF/MAP (whichever it has), and the O2 sensors. These are the sensors that have the biggest effect on mileage, and can be slow to respond without setting off the CEL early in their degradation.

Also, a dose or two of Techron Fuel System Cleaner might help clean out any deposits in the intake and combustion chamber that might be causing you issues.


Hello again–thanks for your speedy response–I’m hoping to speak with my mechanic one day this week and pass along your information–I will let you know what happens–thanks again–Love your show–you guys are not only informative but fun as well!! Have a great week!

Change the thermostat if it’s over 5 years old.

If you are not having a check engine light right now, I’d look for a fuel leak or some form of excess drag.

If you put wider/larger tires on recently, that could be the problem. You give up gas mileage for extra traction. You might tray taking the car up to about 35 mph and put it in neutral and see how far it coasts. It would be nice if you had a reference to work with, but if you have another vehicle, you could do a comparison. If your car slows down quicker than you expect, then have you mechanic put it on a lift and spin each tire to see if one has excess drag.

Another thing your mechanic could do is look for a fuel leak with a sniffer. Might also check for excess fuel pressure, but that should force excess fuel into your engine where the O2 sensor would attempt to lean out the system and set a code if it couldn’t.