deltatech
Veteran Member
My sympathies with you TdiNC. I've had my 2004 Jetta TDI with the BEW engine since 35K miles. Used to get 45 mpg no matter what. Had an accident and now my best is 40mpg. If I ever figure it out I will post it here.
The 10-15 minute trips will be having a penalty since the engine won't have warmed up yet. But the engine will be nice & hot during the weekend trips so that should make up for it....
1. It is my only car and I drive average 120 miles (total) on the weekdays to and from work. Its a mixture of hwy and city. Weekends however, I am generally on a 3 hr drive hwy (approximately 200 miles one way).
2. 10-15 min weekdays and 2.5-3 hrs one way on weekends.
The really important thing is to make sure they never drop below the recommended pressure while the tyre is still cold. Some people (including myself) run with higher pressures, but this is a trade-off between comfort & economy (the ride is much harsher at high pressures). Also, cheap Chinese tyres will bulge & wear on the centre if the pressure is high. Premium tyres handle high pressure well.3. Hwy speed between 70-80 miles per hour.
4. I will get back with the tire pressure.
The 15" wheels are good for MPG, you will notice they will drop a little once you put the 17s on.5. 15 inch wheels (I have hubcaps atm, will be putting on a friends 17inch audi tt stock wheels here in the near future.)
Well, with a roof rack on while doing highway trips at a peak of 80... the aerodynamic drag will be terrible hence low MPG. So I think your MPG is reasonable under the circumstances. If you have space to store your stuff in the boot/trunk/back-seats instead, then you should see your highway MPG improve, particularly if you drop down to 75 or 70 at the same time.6. I do have a Thule roof rack on top as well.
7. Will check lug nut temp after i get home from work.
Even with some of the bad stuff like roof rack and high speed hwy driving don't you think I should be getting better diesel mileage?
Please let me know what you think. Thanks a whole bunch!!!
If I could get a few bank managers into the car I would try and get into over-draftMake sure you are a safe distance back before drafting (2 seconds minimum), particularly if your nearest&dearest are in the car... (however if you are giving a lift to a bunch of tax inspectors, please feel free to draft as near as you like )
When you are steadily cruising at a reasonable speed you aren't using a lot of horsepower, and you won't be at the BSFC peak....
I have always understood that maximum efficiency is situated in the general area around the peak of the torque curve. I.E, for the TDI between 1800-2200 RPM. If memory serves me that is where the best fuel consumption will be, at least for highway driving. This puts you around the legal limit with the gearing on my auto trans.
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Actually, the VNT (VVT) turbos for NA didn't show up in TDI's, until 99.5, with the A4 chassis. Prior to that the turbos were old-school wastegated.From what I understand all the NA TDI's have a VVT?
Actually, the VNT turbo showed up here in 1998, in the New Beetle.Actually, the VNT (VVT) turbos for NA didn't show up in TDI's, until 99.5, with the A4 chassis. Prior to that the turbos were old-school wastegated.
Tony
Oops!Actually, the VNT turbo showed up here in 1998, in the New Beetle.
The highest figures are coming from vehicles with the following:... I see how you guys are posting that you are getting mid 40's-50's se even mid 50's. for the life of me it seems as if I can't get over 38mpg. ...
All the factors Mike mentioned, are indeed working against you.Hey guys how's it going. I see how you guys are posting that you are getting mid 40's-50's se even mid 50's. for the life of me it seems as if I can't get over 38mpg. From my last calculations I got roughly 34mpg. I just recently picked the car up. 2010 JSW with DSG and has 72,000 miles on it. Car has factory 17" wheels and tires (37psi) and I do mostly highway. 25 miles each way with about 5 miles of city at the the beginning and end of each way. I feel like I should be getting in the low 40's and definitely not low 30's. any suggestions?
At least once a week, or more frequently, get on the throttle in 3rd and/or 4th gear when merging on the freeway. And, I mean FULL THROTTLE. This will ensure the turbo vanes are exercised to their full range of motion. BTW...this is also called an Italian tune up.Do these cars get bad carbon build up? What's the best way to clear it out besides hammering down for a few seconds? How often should this be done?
I feel for you on the belly pan, but it is a line of defense for the oil pan. Just a thought. MarkI am running without a lower engine cover or bellypan if you will (replaced it twice because of the snow and ice buildup in this great state of colorado, didnt want to pay for another). .
The skid plate (metal belly pan) is a good choice, bordering on a must-have. I had a car with a Dieselgeek plate, and have one now with an Evolution plate, and I believe they're both excellent products.Been looking at an metal belly pan, EGR cleanout, performance injectors, messing with a chip or scantool with the help of a pro.... But if im getting close to what to what I should I dont want to waste my money. Would love to see 50+mpg again tho.
I bet my average trip was 20-30miles when I bought it. I got 50-55mpg for a solid 6 months after I bought it then a slow steady decline. I blamed it on the sulfer decrease but now im unsure.Those are pretty short trips, and hence you'd get low MPG. Were you doing short trips when you originally bought it?
Ill look into the metal plates.The skid plate (metal belly pan) is a good choice, bordering on a must-have. I had a car with a Dieselgeek plate, and have one now with an Evolution plate, and I believe they're both excellent products.
EGR cleanout can can help restore proper respiration to the engine, and should have a positive effect on fuel efficiency. Not a bad idea to check the snow screen (if you haven't already removed it) and the air filter to make sure all passages are clear.
Here's how I test the air filter (for what it's worth): take a clean dish towel or piece of white paper towel and lay it on the driveway. Take the air filter out of the filter box, hold it level about chest high over the towel, and drop it. If the towel has any significant amount of dirt or chunks on it after you pick up the filter, you need a new air filter. The reason this works is that the dirt would be coming out of the outgoing, not incoming, end, and that indicates a saturated filter.
Do you have the updated MAF sensor? Those help, too. If in doubt, take a look: if it has a tube with a grill over it inside the main tube, it's the new part. If there's a tower-like projection into the middle of the main tube, with no grille, it's the old part. If the car runs as well or better with the MAF unplugged, you need the new part, because the old one is shot.
Personally, I'd do those steps and check for changes to fuel economy, then move on to a tune and/or injectors if you haven't hit the desired MPG mark. It's amazing what easy breathing can do for efficient combustion.
Yes and yes. My mpg has dropped like a brick again this winter, which I find depressing but inevitable.... Forgive me as this is probably a DUUUHHH question, but is that
...many service shops let your tire pressure down to a lower number for the 'ride'. Is that true? ...