New .622 5th gear MPG

Last Friday I drove up to the San Francisco GTG to get an new clutch installed and to swap in a new transmission with a .622 fifth gear.

On the way up I drove a total of 592 miles with 100 or so miles at 2000 rpm (58 mph) and the rest of the time at 2500 rpm (73 mph indicated).
Result 14.812 gallons of fuel and 39.97 mpg.

Route was up I 5 to SR46, west to 101, then south to San Louis Obispo on 101. From there it was up I 5 to I 80 and on to Vallejo, Ca.

For the return trip with the .622 fith gear installed, I filled up in San Leandro, drove down I 5 back to San Diego and filled up with 11.21 gallons. Total miles were 472, so mpg 42.105. Speed was 74 mph, rpm was 2100 and I hit light traffic (for L.A.).

So with the longer 5th gear my mpg improved by 5.34% at very nearly identical road speed.

Also, no a/c on the way up. But ran a/c all the way home.

I had no problem going up the Grapevine at 74 mph (I have the car chip tuned).

Will be interesting to see what I get on my next long weekend trip.

John, glad to hear about the great mileage improvement! Maybe its also because the weight under the hood is about 1.2lbs less. The engine cover is on its way soon.

Put a little taller skinnier tires ( 195-205 / 70 or 75 series ) on and it will make all the gears taller . And you should have no trouble hitting the mid to high 40s in similar conditions .

rotarykid said:

Put a little taller skinnier tires ( 195-205 / 70 or 75 series ) on and it will make all the gears taller . And you should have no trouble hitting the mid to high 40s in similar conditions .

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Think I need to slow down from 75 to get better mpg. Currently running 185/70 x 14 tires with no problems. They are one inch taller than stock.

NewTdi said:

John, glad to hear about the great mileage improvement! Maybe its also because the weight under the hood is about 1.2lbs less. The engine cover is on its way soon.

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No worries on the engine cover. Had a very good time at the GTG. Lots of great people and nice cars. Thanks Andrew.

How did the gear feel I want .658 but everyone says its to low.

racerxtdi said:

How did the gear feel I want .658 but everyone says its to low.

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The gear feels good to me. I had no trouble climbing from the floor of the Central Valley over the 4144 ft Tejon Pass at 75 mph with the cruise control on and the a/c running. Now, I do have a stage III tune from TDtuning.

There is a larger gap between 4th and 5th, but the engine pulls fine from just above 1500 rpm in 5th gear. Naturall, 5th gear acceleration is slower. I had no problem pushing the speed to 85+ to pass when ever I wanted. Another member, Sprocket, also has the .622 5th on his B4V. Sprocket is very happy with it and has no problems or concerns.

Don't know what you are driving, but the B4V is likely bigger/heavier. And I have the 3.157 final drive. Also running 185/70 x 14 tires which are an inch taller than the stock 195/60 x 14 size.

JJ

Of course you got better economy on the way back, it's down hill!!

john.jackson9213 said:

Last Friday I drove up to the San Francisco GTG to get an new clutch installed and to swap in a new transmission with a .622 fifth gear.

On the way up I drove a total of 592 miles with 100 or so miles at 2000 rpm (58 mph) and the rest of the time at 2500 rpm (73 mph indicated).
Result 14.812 gallons of fuel and 39.97 mpg.

Route was up I 5 to SR46, west to 101, then south to San Louis Obispo on 101. From there it was up I 5 to I 80 and on to Vallejo, Ca.

For the return trip with the .622 fith gear installed, I filled up in San Leandro, drove down I 5 back to San Diego and filled up with 11.21 gallons. Total miles were 472, so mpg 42.105. Speed was 74 mph, rpm was 2100 and I hit light traffic (for L.A.).

So with the longer 5th gear my mpg improved by 5.34% at very nearly identical road speed.

Also, no a/c on the way up. But ran a/c all the way home.

I had no problem going up the Grapevine at 74 mph (I have the car chip tuned).

Will be interesting to see what I get on my next long weekend trip.

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Right! http://forums.tdiclub.com/showthread.php?t=217345

Nice gains. .622 FTW!

VWBeamer said:

Of course you got better economy on the way back, it's down hill!!

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You are being funny? Right?

Check out the two routs with Google earth. You will see both routes are very similar for altitude change. San Leandro is 180 feet above sea level. Vallejo is 155 ft. where I started. Home is at 653 feet. Tejon Pass is the highest point on the trip. Went over it both ways. Other than that 1500 is about the highest point on both routes.

Realise this is just 2 data points. But I did try to post as much as I could so others could evaluate the conditions underlying my data points. BTW, temperatures were close. The run up started at 4 a.m. hence no a/c. the ruturn trip started at 11 a.m. and the a/c was used on low the entire trip. Hit some stop and go traffic on the 210 in L.A. but moved to the car pool lanes to get away from that.

For a Top Gun your not very quick with the jokes....maybe I'm not funny...oH well, I entertain myself...

VWBeamer said:

For a Top Gun your not very quick with the jokes....maybe I'm not funny...oH well, I entertain myself...

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It is funny!

The Top Gun ref. in my sig relates to the movie - Certainly not me!!!
Just the closest land mark to my home in San Diego. Now Miramar Marine Air Station.

What's the Vw part number for the .622 gear please ?

Jakub said:

What's the Vw part number for the .622 gear please ?

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Also, where did you buy it?