Why would a custom aftermarket tune improve fuel economy if the factory stock is tuned for the daily driving, non performance driver. Wouldn't it make sense for Ford to have a fuel efficient stock tune for the car coming from the factory?

 

More power = easier to get car moving = better mpg.

 

Ehhhh... not quite right but ok

 

My guess is that the tune is leaning out the mixture under load...the stock tune likely runs a bit fatter for knock protection at the cost of a bit of fuel economy.

This is also why tunes usually demand premium fuel and some common sense when flogging the car on a hot day to avoid a knock or a scorched piston.

 

 

This is correct

 

So having a performance tune is detrimental to the motor in the long term?

 

No

 

Not necessarily....but you will be more at risk for detonation which could be catastrophic...and presumably you will be running hotter which will over the long term will shorten the life of gaskets, belts, hoses...probably bearings, etc.

Go with a reputable tuner, set it up for one grade lower than you can regularly purchase (i.e. tune for 91 octane, run 93 octane gas) and you'll probably be fine for a long time.

Ford provides a warranty on the motor so they set it up to be durable and safe. Tuning eliminates that margin of safety...and voids your warranty even of you replace the stock tune.

 

The fuel economy gain is a result of the tuner not having to meet emissions, and can run leaner than stock in low load conditions, especially if the cats are removed and damage to them is not a concern.

 

Personally I'm really not concerned about fuel economy, but rather look for satisfactory performance. I'm running the Steeda CAI with the Steeda 93 octane tune, and I couldn't be happier. If I wanted to look for fuel economy, I would have bought a Prius! Lol (just kidding!)

 

A aftermarket tune MAY improve fuel economy because of the improved Spark tables across the entire RPM range and more efficient fuel tables in the higher RPM load ranges.

The manufacturers have to ensure that their programming will make it through tough emissions standards while maintaining their fuel efficiency for all octane fuels, and altitudes too.

When OUR custom tune files are created we begin from their starting point and adjust for items such as specific a/f targets, different timing levels dependent on requested octanes from customers, and additional horsepower and torque.

Now for " leaning fuel at WOT " we adjust the command a/f ratio to well within .2-.5 of a point of stock, for example if a factory PCM is commanding 12.5 we may move that to 12.7:1. There again this is ONLY an example because my a/f calculations are dependent on Hp level, weight of the car, auto or manual, and many other variations. Wieght of the car impacts my fuel calculations tremendously. Also the above is not what I command on a 2011-up.

Another reason you may see a fuel economy increase is with the more efficient timing tables you will of course see a increase in horsepower and torque. This in turn will make it easier for the engine to do the same work and require less fuel to do it.

Think of it like Ford does with the trucks, if a V6 installed in a crew-cab F150 was the best for economy then why offer a V8? Because in truth a n/a V6, in the same truck body as a V8, will not get the same economy nor have the additional power.

Turbocharged V6's such as the Ecoboost will but you have to force more air into them. Yes, FI is the replacement for displacement, lol.

So, in short yes you MAY gain fuel economy from improved spark and fuel curves from our aftermarket tune files. Still, I dont quote these gains using them because EVERYONE's driving conditions are different. What I will say is that you will not loose any MPG's over your current factory tune on your vehicle and you may notice an increase but you WILL notice a much nicer to drive vehicle with additional power.

All of the above is about our C&L files, nothing is said towards any other aftermarket tuning.

Thanks!! Doug