This is probably one of the lesser intelligent questions asked on this forum but...

Does installing the 4.57s with the yellow box affect gas milage, and if so how significant?

also just wondering what kinda gas you put in ur car? i think premium is recommended but how does mid-grade work out?

im prepared to be flamed for this post so go ahead and do what you will...

 

For one, the Yellow box has no role for gas mileage. It only corrects the speedo to read right.

Second, it logically should lower your mileage. this is because of the math, but in reality we have seen both higher and lower milage. I think has to do with the effort needed to move the car is less and the way the driver drives. So there is no clear anwser to this question.

 

If you do more freeway driving, your mileage will likely go down. If you do more city driving, your mileage will likely go up.

Mine went up an average of 3-4mpg.

 

Yes, premium fuel is recommended. You should not diverge from this. However, your car will run on mid-grade fuel or even regular fuel as the ECU will compensate. It won't damage anything but you won't get the full benefit of the better fuel. You will lack power and cause a significant timing change. It is not the best way to go.

As already said, highway cruising in 6th gear will see increased fuel usage. I dropped 4 miles/imperial gallon when I went to 4.44s.
You "may" see an increase in fuel economy in city driving "if" you do what most people with gears do. That is, we tend to use one gear higher at the same road speeds as when we had the OEM gearing. This reduces the engine rpm in your usual city driving routine. If you used to run 3rd gear at say 35 to 40 mph with the OEM gears and you continue to run 3rd gear with 4.57s, then you should see increased fuel use as the engine is turning over faster. However, I for one, have gone to 4th in the same scenario.

 

thanks for the input guys it helps. i just mentioned the yellow box because i figured its something u NEED to install when u get the gears...

i kinda do a mix between city and highway driving equally so i'm in the middle about the whole thing... what do you guys think? is it worth it?

 

I will opt out of this question. Since I am the gears vendor, I am bias, or my view could be seen as such. So with that in mind.

Personally I like the added get up and go. I have had them on my car for 2+years now.

 

im starting to think the 4.44 gears would be a better bet for me since im so cheap on gas haha. i figure there would be a smaller loss in mileage but still a good enough gain in the GO department.

anyone know how the 4.44s feel? still good gain?

 

You NEED the Yellow Box for speedometer compensation. Without it, you will be reading a higher speed than what you are actually going and your odometer will rack up miles faster than you are actually going. It has nothing to do with fuel economy. If fact, if you don't get the Yellow Box, you'll register the same fuel economy as before since your speedo and odo will be out but in the real world, you won't have travelled nearly as far for the fuel used.

I have the 4.44s and they still give a good "punch". The only problem is the world supply has nearly dried up. Unless you find a used set or a set that someone has had sitting around for all this time, you will have a very hard time getting a set.

Here's the difference:
4.44 = 8.3% gear reduction
4.57 = 11.5% gear reduction

This would represent the percentage mechanical advantage and thus, the same percentage higher engine speed if all else remained equal. The same can be said about the speed and distance error that the YB must compensate for.

 

I absolutely LOVE my 4.57 gears and am probably one of the bigger advocates on the site regarding them. I would never go back!!

I chose the 4.57 not only for strength, but also because they offered an excellent compromise between the 4.44 and 4.77. 4.77 revs on the freeway were too high for me. 4.44 I wanted just a tad more "oomph" than that. 4.57 were just right.