Need MAX MPG-- HELP!!!

Need MAX MPG-- HELP!!!

I need the advice of the Great Ones of the TDI club. Recently I added a second TDI to the stable. A 2003 Golf 5 speed which my fiance will be driving 800 miles per week to go to lawschool. I've had an 03 Jetta TDI since new so all the basic things are done. (Ventectomy, 44psi tires, etc) But still, I want Maximum MPG potential. Aside from driving suggestions I need to have some mechanical suggestions. Do I chip? Tuning box? or something else. (6th gear would be really nice right about now).
any advice would be appreciated.
Jerry

Need MAX MPG-- HELP!!!

Michelin Energy Tires, or Continental touring tires may help. They are both designed to give max. fuel economy.
Most new cars are equipped with these tires for this reason.

Other than that there isn't much else. I did see a Ford V10 on the highway doing 55mph with his side mirrors folded in!! Boy it must hurt to operate that rig.

Need MAX MPG-- HELP!!!

I was wondering who would acknowledge the title as one of the "Great Ones" and chime in on this.

I didn't respond directly because 1) I'm not that great, and 2) I've got nothing.

Jerry said he was looking for suggestions "aside from driving suggestions. And after you inflate the tires properly, nearly everything you can do to improve mileage is related to how you drive.

Need MAX MPG-- HELP!!!

You gotta keep your speed to be at about 2000 RPM in fifth to get great mileage (maybe 1800 rpm). Tuning box? No! Either injectors or chip. If you keep off the power, either of these will net you approx 1-2 mpg. (some get more than that, some stay the same). It all comes down to driving style really. There are minor things, but if you are looking at cost vs mileage gains, you will have to drive a heck of a lot of miles to recoup the costs of anything to upgrade mileage.

Need MAX MPG-- HELP!!!

You ought to see how much it hurts to drive a 04.5 4 wheel drive dodge diesel, in automatic no less. The very reason I am trying to find a nice used tdi jetta, bug or golf in which to drive on a regular basis.

Need MAX MPG-- HELP!!!

You gotta keep your speed to be at about 2000 RPM in fifth to get great mileage (maybe 1800 rpm). Tuning box? No! Either injectors or chip. If you keep off the power, either of these will net you approx 1-2 mpg. (some get more than that, some stay the same). It all comes down to driving style really. There are minor things, but if you are looking at cost vs mileage gains, you will have to drive a heck of a lot of miles to recoup the costs of anything to upgrade mileage.

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what does this equate to in a 5 spd mph wise.
I have an automatic.. 2000 rpm on the highway is about
55 mph


..

Need MAX MPG-- HELP!!!

I hope you're not in California because driving at 2000 RPM on the freeway in 5th will get you killed.

Need MAX MPG-- HELP!!!

Stay out of the 1.9's torque hole between 2600-2800 rpm for cruising.

cruise at about 26xx rpm (primary torque peak)translates to 77 mph for my 5 speed

Need MAX MPG-- HELP!!!

yup got my best (and safest) mpg at 2500RPMs

Need MAX MPG-- HELP!!!

Stay out of the 1.9's torque hole between 2600-2800 rpm for cruising.

cruise at about 26xx rpm (primary torque peak)translates to 77 mph for my 5 speed

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Nick, could you explain this further? I'm usually cruising at 2800-2900 rpm in 5th.

Need MAX MPG-- HELP!!!

Stay out of the 1.9's torque hole between 2600-2800 rpm for cruising.

cruise at about 26xx rpm (primary torque peak)translates to 77 mph for my 5 speed

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Hey Nick-

You didn't respond to my other questions on your observed "torque hole" on the "High Speed Fuel Consumption" thread, so I'll ask again here:
What torque holes do you refer to? If you see a drop in power at 2600-2800 rpm, you have a problem- probably your MAF is failing or you have restricted airflow through clogged filter or snowscreen. I am confident in stating this because I experienced that and it was fixed with a MAF replacement.

The 1.9 TDI develops max torque at 1900 rpm, regardless of which gear you are in. Cruising near this is going to obtain the best fuel economy. There is also wind resistance to take into consideration. Jonathan Bartlett, who I consider to be one of the mileage gurus, has stated before that he thought 1750 rpm in 5th gear nets you the best fuel economy. He was probably claiming this on his observations with a B4 Passat, but it won't be much different in the A4 (Golf or Jetta).

Sorry, Jerry, I am not one of the gurus to suggest any mechanical changes. I think 90% of the fuel economy potential of these cars is realiazed in how you drive them, and not how you tweak. Keeping the revs low in 5th gear is the best you can do.

-tom

Need MAX MPG-- HELP!!!

I posted this over at the TDI-PD forum, but I wanted also to post it here. I'm a bit confused now after reading this discussion.

I have a TDI New Beetle equipped with the DSG automatic tranny. I have six forward speeds.

What RPM would give me maximum fuel economy in sixth gear?

Is it 2,000 or 2,500??

Thanks for your thoughts.

Need MAX MPG-- HELP!!!

I posted over at the other thread. 2000 rpm is more economical- if you can do it safely.

-tom

Need MAX MPG-- HELP!!!

for -MAX- MPGs get few great audio books and set the cruise on 45mph. for very good MPGs do the same at 60mph.

Need MAX MPG-- HELP!!!

Okay, driving habits are very important-- I am doing very well, drive smoothly, use cruise control on trips.

The speed I like to drive is 65, clearly above optimum for best mpg. This raises the question of increasing gear ratio(is that right?) or increasing tire diameter to lower rpm.

To carry this further, I was looking at a pair of engine (fuel consumption) maps in a book the other day, one for a diesel, the other for gasoline. Superimposed on the maps was the usual operating line for the cars. I noted that the operating lines are way off from the peak efficiency areas on both graphs. The peak efficiency areas are near the top of the map and usually at the rpm for max torque.

On an engine map, it is customary to plot rpm on the x-axis and torque for the y-axis. The operating lines are very low, showing that a typical operating point is using much less torque than the engine can deliver for that rpm. (Same for both gas and diesel.) Practically, this is a pleasant way to drive-- you can accelerate well just by stomping on the pedal. If you operate in the best-efficiency area, then you are turning the engine at low rpm, but developing nearly the maximum torque there. This means if you need to accelerate, first you will need to shift down, then bring up the torque again.

Well, what does it mean? Driving 40 mph in fifth gear, I would say, or better still, changing the gearing (tire size?) so that you can keep the engine on the low side of max torque rpm while cruising at your favorite highway speed. Subject, of course, to the understanding that aero drag rises as v squared.

Finally, we must admit that the engines we have are far to large for best fuel economy, but we do like it that way.

Ernie Rogers

Need MAX MPG-- HELP!!!

I have to disagree with the keep it at 2000 rpms theroy. If you've got a boost gauge you'll notice that at 2000 rpms going up a hill you'll be at 10+psi Thats not a good thing for MAX mpg.

I assume you driving is on the freeway where you can't drive 55-60mph.. right? So I'd recommend a few things.
<ul type="square"> [*]lighter rims 15" or 16" prefer the 15" [*]lighter tires with MAX psi [*] [*]PowerPlus Nozzles if you can find the PP357 or PP520 [*]racepipe because of the Higher RPMS on the freeway [*]Boost guage I'll explain on the bottom [*]Oldman Intake with heat reflective tape www.designengineering.com [*]removal of the CAT might help in a small way [/list]


The Boost gauge is your best way to get the highest MPG. How? you can watch your boost levels and limit the loss from high boost pressure. It can be used like an instant fuel use display. <font color="red">more boost = more fuel = more heat = less MPG </font>

I used to own a Hybrid honda Insight and that car would teach you how to drive to get the best MPG. As you approach a hill load the engine slighty 1-2% increase. This will raise your speed. Once your going up the hill watch that boost gauge. Limit the rise in boost. This will also cause the speed to drop slighty. Which is why you speed up before the hill. After you have driven like this for a few weeks it will become second nature. You know exactly how much pedal pressure to increae or let off.

Need MAX MPG-- HELP!!!

as winter weather comes you can tape off your lower grille. This will keep the engine warm and improve the aero.

Need MAX MPG-- HELP!!!

On second thought, it must be the tach that is mis-calibrated and not the speedo. You said you checked the speedo against a stopwatch.

Does anyone know if the tach can be calibrated via VAG-COM?

Need MAX MPG-- HELP!!!

Jerry,

My purchased used at 45k 2000 Jetta has averaged over 51 mpg in the almost 30 months I have owned it. I have driven it 80,526 miles according to my Excel Spreadsheet ........ totally stock with only one modification. I did the EGR mod back in July of this year. (shows milage improvement too!)

I typically drive about 68 MPH on the expressway (yes in the slow-lane while the world passes by). I think the RPM is about 2375 at 67 to 68 MPH. Yes, there are times that I do get up near 80 MPH, but rarely. My round trip commute is about 84 miles with 54 of those on the express-way with the balance on two lane roads with practically no traffic lights ...... that makes a big difference.

Recently I took a road trip to Florida (I-75, to I-40 at Knoxville, over to I-26 at Ashville, NC, then down I-95). At 582 miles I filled-up (to avoid the high prices in Florida). The tank gave me 56.69 mpg. We stopped four times, three at rest areas and the last stop was for the fuel. The balance of the trip involved "city driving" and on the return we were high-tailing out of Florida to beat Hurricane Frances and also to get to my brother's place in Gainsville, GA at a reasonale hour. So, that leg of the trip came in at a little over 53 mpg.

As I review the MPG Graph in the Excel spreadsheet it is quite obvious that spring and fall driving yeild the best fuel enconomy. I suppose this is due to limited use of the Air Conditioner and the "warm-up" fuel usage in the winter months........Summer driving yeilds the worst fuel economy!

my two cents worth ...... hope its helpful.

Need MAX MPG-- HELP!!!

Stay out of the 1.9's torque hole between 2600-2800 rpm for cruising.

cruise at about 26xx rpm (primary torque peak)translates to 77 mph for my 5 speed

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Hey Nick-

You didn't respond to my other questions on your observed "torque hole" on the "High Speed Fuel Consumption" thread, so I'll ask again here:
What torque holes do you refer to? If you see a drop in power at 2600-2800 rpm, you have a problem- probably your MAF is failing or you have restricted airflow through clogged filter or snowscreen. I am confident in stating this because I experienced that and it was fixed with a MAF replacement.

The 1.9 TDI develops max torque at 1900 rpm, regardless of which gear you are in. Cruising near this is going to obtain the best fuel economy. There is also wind resistance to take into consideration. Jonathan Bartlett, who I consider to be one of the mileage gurus, has stated before that he thought 1750 rpm in 5th gear nets you the best fuel economy. He was probably claiming this on his observations with a B4 Passat, but it won't be much different in the A4 (Golf or Jetta).

Sorry, Jerry, I am not one of the gurus to suggest any mechanical changes. I think 90% of the fuel economy potential of these cars is realiazed in how you drive them, and not how you tweak. Keeping the revs low in 5th gear is the best you can do.

-tom

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Tom,

I've been off the boards for a while... Well, I cleaned out the snowscreen but it still seems like I have a bit of a power hole between 26xx-2800 rpm's, although less noticeable. On another note, I am wondering if putting synthetic amsoil gear lube in my manny tranny will net better mpg? I just bought it (used) and don't know what's in it...probably what it came with from factory(?)

Also, previous owner ran castrol syntec every 5K miles. I think I'll go with amsoil 5W-30. (or is there something better in a 0W-30?

My mileage has been around 45....I'm envious of people getting 50. What else can I do? My tires are at 44.

Btw: 1750 rpm in 5th gear is suuuuuuuuuuuuuuuuuuuuuuper slow. Sorry, I don't have patience to go <68 mph.

Need MAX MPG-- HELP!!!

Also, previous owner ran castrol syntec every 5K miles. I think I'll go with amsoil 5W-30. (or is there something better in a 0W-30?

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Amsoil makes a very fine 5w40 motor oil, that meets the specs for TDIs and is highly recommended by quite a few members. The 0w30 would be an inferior choice.

Need MAX MPG-- HELP!!!

I bet if you drove 55 to 65 mph you'll get near 50 MPG. Doing 70 mph might make too.

I drove 120 miles a day to and from work for some full-time temporary work this past summer. Drove 55 mph (the speed limit on the road) most of the time. At 55 or 60 mph the RPMs in 5th gear are right around 2000. My MPGs were: 58.36, 54.37, 54.71, 55.99, 55.03, and 55.94.

Need MAX MPG-- HELP!!!

Thanks Tornado. This stuff is so hard to find. I'm just going to have to buy the amsoil 3000 series off the internet for $6.00/Qt. + shipping, I guess.

So what's the verdict on the apparent power hole (26xx-2800) rpm? It's not that bad, just sort of a weak spot in the powerband. MAF bad now or starting to fail?

Any ideas about the gear oil? Does it really help? I remember a post on here a while back where someone said it really helped, and amsoil says it can net ~4% increase...

Need MAX MPG-- HELP!!!

Nick-

The power hole you describe is very likely due to a failed MAF. If you are near someone with a VAG-COM, they can check its output to see if it is the default setting- which evidently leads to doggish performance in the upper gears (at least it did with me). This is a $90 part that takes about 5 minutes to replace. These have been going out at a very high rate on the A4 vehicles. Believe me, if you drove across the country in a vehicle with a failing MAF and still enjoyed it- you are in for a very pleasant surprise on how much better they operate with a fully functional MAF! Seriously, do this before messing with your tranny fluid.

-30 wt oil is too thin for your engine, unless you are in a very cold winter climate. Use an oil that meets the correct VW spec for your car (505.00) and is made for diesel engines. VW specs 5W40 for NA TDI's.

Although many people advocate running your tires at the max cold rating on the sidewall, my personal experience doesn't show much difference in mileage from the max load rating on the fuel filler door, and I believe it is safer to use a vehicle manufacturers suggested rating because they designed the car and know the suspension settings, weight distribution, etc.

The original poster was asking how to get max mpg's- that's where the 1750 rpm applies. Very few people can drive at this speed for sustained periods.
-tom

Need MAX MPG-- HELP!!!

Thanks Tornado. This stuff is so hard to find. I'm just going to have to buy the amsoil 3000 series off the internet for $6.00/Qt. + shipping, I guess.

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I thought the whole purpose of buying Amsoil products was, you tell the local distributor what you want and he gets it for you?

If you can't get Amsoil 5w40 synthetic, rated API CI-4, then go to Schucks or Kragen and buy Mobil-1 Truck and SUV.

Need MAX MPG-- HELP!!!

Thanks Tornado. This stuff is so hard to find. I'm just going to have to buy the amsoil 3000 series off the internet for $6.00/Qt. + shipping, I guess.

Click to expand...

I thought the whole purpose of buying Amsoil products was, you tell the local distributor what you want and he gets it for you?

If you can't get Amsoil 5w40 synthetic, rated API CI-4, then go to Schucks or Kragen and buy Mobil-1 Truck and SUV.

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err, in theory.

Amsoil is completely unheard of on the west coast. My local Shucks people look at me stupid when I say I need oil for my diesel and point to the Delo 400.

Need MAX MPG-- HELP!!!

If you can't get Amsoil 5w40 synthetic, rated API CI-4, then go to Schucks or Kragen and buy Mobil-1 Truck and SUV.

Click to expand...

Amsoil is completely unheard of on the west coast. My local Shucks people look at me stupid when I say I need oil for my diesel and point to the Delo 400.

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I believe Schucks, Kragen, and Checker are all branches of the same company. And if one store doesn't have Mobil-1 Truck & SUV, they can surely order some. Autozone might be able to get it, too, but I don't think I've seen it at any Autozones yet.

It really is good stuff. Worth buying a whole case, if the store manager won't order it otherwise. They were running an unadvertised special on it at Kragen, the last time I bought some -- $3.79 or $3.99, I think.

As for the Amsoil 5w40 (CI-4 rated), I've heard very good things about that, too. But I would not consider any other weight of Amsoil motor oil.

Need MAX MPG-- HELP!!!

Just thought I would add this quote from BiodieselcleveOH for sale description of his 97 passat. "I average 56 mpg. At a steady 60 mph on the highway in the summer, I get 61 M.P.G." His numbers are very impressive especially the 61 M.P.G. Whenever I get my TDI I will probably do some of the mods he has done.
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