Last post on Sep 02, 2012 at 1:44 PM
You are in the Volkswagen Golf
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Volkswagen New Beetle, Volkswagen Golf, Volkswagen Jetta, Volkswagen Passat, Diesel, Hatchback, Sedan, Wagon
#1506 of 2551 Re: 2000 golf TDI [bpeebles]
Feb 23, 2005 (4:18 pm)
my 2004 vw golf 10,000 miles has never gotten over 41 mpg. acceleration isn't a problem. i'm kind of wondering what i'm doing wrong. last summer had roof rack on so that might have brought it down. this winter i'm still getting about 41 mpg. even on the highway i still get low 40s mpg. the guy who sold me the car said shift up as soon as you can to get best mileage...so i rarely shift at or above 3000 rpms. frankly the engine sounds like its working too hard once it gets up toward 3000. i'm not looking to race around with it, but from what i read here it sounds like racing around with it gets the better mpg. that's different from a "normal" car?
another question...do you improve mpg by coasting?
#1507 of 2551 Re: 2000 golf TDI [jkg511]
Feb 23, 2005 (4:48 pm)
To answer your 2 questions:
1)The TDI engine is most efficent at 1800 RPM (the torque peak)(about 40MPH in fourth gear and 57MPH in 5th gear)
2)You get maximum MPG during decellerration in gear. (Like all fuel-injected engines there is ZERO fuel injected under this conditon.)
Pushing the clutch in or decellerating in neutral forces the engine to inject fuel to keep it idling this uses some fuel.
The suggestion to shift ABOVE 3000 RPM is to reduce plugging of the turbocharger VNT vanes, intercooler and intake manifold. Full-throttle accelleration should be used at least twice for each tank of fuel....again to keep things cleaned out. Once it starts to plug up... often the only remedy is to remove the parts and manually clean them. Puttsing around with a TDI engine is a sure way to invite problems.
No one is suggesting that you "race around", there is no need to go fast, just ACCELLERATE BRISKLY to the legal speed limit.
At 10,000 miles, your engine is barely even starting to break in. If you have been babying the engine for the first 10,000 miles, you may have created poorly seated rings. On any new engine, the best way to seat the rings is to use bursts of full-throttle accelleration after the initial wear-in. It is also important to follow the accelleration bursts with some coasting in gear. (This also helps the rings to seat)
People that actually MEASURE the compression on TDI engines have reported that the TDI engine will increase MPG during the first 20K to 30K miles as the rings start to seal well.
After the first 500 miles on my TDI, I concensesly loaded the engine up a long, steep hill and coasted back down once a day for several weeks.
#1509 of 2551 Re: 2000 golf TDI [bpeebles]
Feb 23, 2005 (5:58 pm)
this is great help, bpeebles. I really appreciate it!
#1510 of 2551 2004 golf TDI [jkg511]
Feb 23, 2005 (6:00 pm)
(jkg511) Just as a side-note, have you been making sure that the oil that is in your PD engine meets the VW 505.01 specificaiton?
Even many VW dealerships have been putting the wrong oil in those PD engines.
Here is a photo of the ONLY allowable oils to be used in the 2004 TDI PD engine.
#1511 of 2551 Re: 2004 golf TDI [bpeebles]
Feb 23, 2005 (6:30 pm)
And as an additional side note.....
It seems the PD engines are getting a bit less mpg than some of the older non-PD motors. Mine gained about 2mpg overall between 0-20k miles. I'm sitting on about 46mpg overall. I can get 50mpg on all highway trips, running pretty swiftly. So potentially if the PD's are off a mpg or two anyway, plus you've got a green engine...I think 41mpg is realistic. Mine is an '00 TDI btw.
I also didn't notice what type of driving you're doing. If it's heavily city, stop/go, 41mpg "ain't too shabby".
#1512 of 2551 Response to JANPRIDE2 re TDI normal performance
Feb 24, 2005 (12:56 pm)
Thank you everyone! I have been out of touch and am surprised and grateful at all the comments and guidance. Now to begin looking for the talent that can help me with the MAF diagnosis. I look forward to a positive change. My last auto (up to a year ago when I bought this TDI) was a basic 1986 Jetta and I was always pleased enough by it's acceleration performance. Currently my TDI could not keep up nor go as fast.
Meanwhile, anyone care to comment on risk of delaying timing belt changing? My 2001 Jetta TDI is near 64000. I understand the reccomended change is at 60000. I also know that if it breaks the valves will get bent. I am thinking more about risk verses oportunity and cash reserve.
Again, thanks to all.
#1513 of 2551 Re: Response to JANPRIDE2 re TDI normal performance [janpride2]
Feb 24, 2005 (3:09 pm)
Start thinking about the timingbelt change soon.
Make sure somone that had actually knows TDIs does the work. (some folks have reported bent valves because a new belt was installted incorrectly)
Additionally, do not forget that the waterpump and timingbelt adjuster must be replaced at the same time. (they wont last another 60K miles)
There is a moter-mount bolt that must be removed and REPLACED with a new one when the TD is changed. VWs use special "stretch bolts" that are only good for one tightening. (some folks have reported the engine almost falling out because they tried to save a few dollers and reused the old bolt.)
#1514 of 2551 Re: How about some tires? [vzh9p7]
Feb 24, 2005 (3:30 pm)
By now, you may have already purchased the replacements. But I just saw your posting about tires. My original set lasted until around 60K but I had an alignment problem that caused uneven wear.
Once fixed, the alignment has held better than any other car I have owned. When I went to buy replacement tires, I found that the OEM Michelins were rated to 110 MPH! The ones just below them in performance were only rated to 90 MPH but had a longer tread life guarantee. Best of all, they were cheaper. The tire salesman couldn't convince me that a diesel car would need 110 mph tires. Of course, I'd rather slow down and push up the fuel mileage. Good luck.
#1515 of 2551 BP ECD-1 ULSD
Feb 24, 2005 (5:04 pm)
Is anyone running the Ultra low sulfur diesel in their new TDI? I am curious if the lack of sulfur causes engine damage as it supposedly does in big diesel engines. I have a station very close to me that sells it. Slightly more expensive than regular #2 diesel.