Have you guys that have re-tuned with SCT or Diablo actually calculated your mileage the old way?

I found this in the knowledgebase on Diablo's website:

Predator: After using the predator in my vehicle, the computer MPG is showing different than manually measured values. Is that normal?

Yes it is. The tuning affects many parameters throughout the engine management system (ie: the fuel flow calculation, etc.) and therefore the MPG indication. The Predator is made for off-road use only. We put all efforts into maximizing HP instead of calibrating "comforts" like MPG indicators.
Last update: 2005-01-07 22:53
Author: Keith Korchma

Here's another article:

Predator: How will the Predator affect my fuel consumption or MPG?

The Predator generally gives an increase in mileage, however this is very dependent upon driving style. The increase in MPG is a by-product of maximized engine efficiency, improved timing curves and a more complete combustion of air/fuel ratio (ie: the engine extracts more power from each molecule of gasoline, hence better MPG). We also offer special lower octane files for use with regular grade fuel as well.
Last update: 2005-01-06 13:36
Author: Ivan Kotzig

 

WOW!! I wonder how the 4.10 gear folks are doing gas mileage wise???
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aggressive in town driving ~15mpg. cruise control at 75 in 5th, 24-26

 

No, good point. I will, in fact, do so on the next fillup. Normally, though, at the 3/4 tank point, I'd go 80 miles or so, but this morning it was at 116. Very rough eyeballing, but fairly consistent. So I DO think there's been some improvement, but the research notes you found are a good reality check.

John

 

No, good point. I will, in fact, do so on the next fillup. Normally, though, at the 3/4 tank point, I'd go 80 miles or so, but this morning it was at 116. Very rough eyeballing, but fairly consistent. So I DO think there's been some improvement, but the research notes you found are a good reality check.

John
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Re-tuning is generally good for gas mileage as the second FAQ indicates but I suspect that the computer might be indicating more of an increase than in reality. I'll be tuning soon but probably not before your next fill so I look forward to hearing what you calculate and what the computer said!

 

I have a totally bone stock 2007 GT with factory 3.55s and the Tr-3650. Cruising on the highway at 65-70 mph nets me about 23-24 mpg on average using Meijer 87 octane gas. I could never get higher than this but I only have about 4000 miles on the car.

 

I did a 300 mile trip this morning out and back. Reset avg about 20 miles into the trip 97% highway 65-80 cruise set. 2 stops at rest areas, 5 miles of back roads 45 mph. 1 stop for food and another for gas Using the trip computer my avg when getting home was 26 on the money.

 

My car has 2800 miles on it and averages 27.5 on the highway and 17 in the city. completly stock

 

Just did a highway trip, got between 25 & 26 mpg. Average speed, 65 with cruise, have drop in airaid filter and 87 perf tune.

 

2000 miles... before the CAI/tune was averaging 14mpg combined (50/50 city/highway). Now I average 13mpg after the cai/tune.

I'm hoping it will get better with time?

 

just over 500 miles and I got 20.XX mpg on my first fill-up... lol. I have the newly stock 3.31 gears and a happy new foot. lol.

Sounds like a great mileage to me, John!

 

Did my first fill up today after leaving the dealership with a full tank on Wednesday evening. Bone stock, 3.55 rear end, 5 speed, ..........257.3 miles and it took 12.5 gallons to top it off. Roughly 20.584 MPG. Combination of interstate and small twisty back road driving.

 

This is about where I was before the CAI and the Brenspeed 93 octane tune. I left the gas station and took an all hiway trip for about 1 hour and it bumped 29 miles per gallon just as I turned off the highway. I have the same gears and transmission. It is awsome to have that kind of performance and get good gas mileage also (if you keep your foot out of it).
I was cruising between 65 and 70.

Im not sure but I don't think you will benefit from higher octane fuel if you are totally stock.

 

On my way to work this morning, cursing at 50mph in 5th the computer showed 33mpg. On the highway at 70mph, I can usually get upper 27-28mpg. Anything under 100mph, and I can still get at least 25mpg.

 

1550GT: I used to use 93 octane in my 00 Vic because of the tune and never saw a mileage increase. I'd have to see a consistent increase of about 1-3 mpg to justify the extra cost, but the 93 octane would run through the system like junk food and not get completely burned. I wish I hadn't ordered the 3.55s so I could get even better gas mileage with the 3.31s!

 

I think do experience a mileage increase if you use 93 octane with a 93 octane tune. (I personally haven't experienced it, because I can't keep my foot off the pedal anymore.)

 

I have the 91 octane race tune, I get 19.5 - 20.0 mix of highway, stop and go highway, and street. If I run 65 MPH for an extended trip with no stops, I can break 25MPG with no problems with my 4:10's. One I cross 75MPH however, it's like someone drilled a hole in my gas tank.

 

I was getting around 19.5 around town until the 4.10's were put in. Now its around 17.7. Just added a dyno tune and a spydershaft and I hope for some improvement in mpg - just have to keep my foot out of it.

 

I only experienced it for just that one hour. Its too hard to stay out of the throtle with a tune on it and and aftermarket exhaust.

 

Wow, there's some low numbers going on. When on a long highway cruise, I typically make between 30-35mpg. In the traffic I make only 16mpg though. Except for a CAI and exhaust, my go-mechanics are stock.

Big engines usually do best at highway speeds anyway.

 

on average 75 round trip to work taking 2 hrs. in traffic, averaging 22.2 mpg. with 3.55 gears and 3500 miles on od
currently bone stock.....for now.