High Mileage Computer?

I’ve heard that police cars have different ignition computers in them that allows them to go faster. Does anyone make a computer replacement that will cause the car to run more conservatively? What about a programmable computer?

The computer is no different. It simply has different programming in it that has a higher rev limit. You can buy a “tune” for many vehicles. Some are not emissions compliant. Most are driven towards less efficiency and more power. Year, make and model information would be a good start…

Twin has it right. It does depend on what car how much if anything you can do. Some require just a little computer tweaking others require a computer replacement. To get the most out of it, it usually requires some hardware changes as well. Police cars are not the same as the civilian counterpart. Also as noted some do not meet pollution standards.

It should also be added that some can cause you some problems, in reliability for example and mileage for most of them.

Don’t expect too much change in most cars unless you are ready to put a lot of dollars into the project and do both hardware and software changes.

Contrary to popular belief, all police cars on the road today must meet the same emissions standards as civilian passenger cars. They may have slightly modified rev limits, shift points, and the like, but for the most part, the powertrain is the same. The Impala police car has the exact same 3.9L V6 as the civilian car, the Crown Vic has the exact same V8 as the civilian car (although it makes about 11 more hp) and the Charger police cars often have the same 3.5L V6 as in the civilian cars.

True, 20 or 30 years ago police cars had bigger, more powerful engines, but not anymore. Where police cars differ most from civilians is in the suspension system - it is made for severe duty use, and can take one hell of a beating. And really, most police cars aren’t in high speed chases, but tool around cities, bouncing over curbs and potholes, and sitting around idling.

By the way, you can buy a ‘tune’ for your car’s computer - it often will come in a OBD2 reader, which will pretty much rewrite your car’s factory programming with more efficient (or powerful) timing, rev limits, shift points, etc. However, they seem to cost in the $200-300 range and up. Personally, I don’t think it’s worth it.

Depending on the car you have the computer may be programmable to reset the rev limit and some other mapping. It sort of depends on what you mean by “more conservative.” If you want better fuel mileage, I doubt you’ll get much improvement over the factory settings, but it you want overall less power and torque to keep a throttle happy teenager in check, then maybe you can get it tuned down a bit.

You can certainly buy aftermarket engine management computers that you can reprogram to your heart’s content. Here is a link to one such system: http://www.emsnorthamerica.com/

I have never used one of these, but I checked and it does have programmable hard and soft rev limits. But these are $1000 units for the low end version.

I REALLY HATE this term of reprogramming…because it has NOTHING to do with programming. The program that runs on these computers (chips) does NOT change. All that is done when “re-programmed” is the memory table values are changed. This causes the PROGRAM to operate differently depending on what the values are. You are really limited on what Values can be changed and what ranges that allow the car to run properly.

In the case of the P-71 Crown Vic, the top speed is allowed to reach 136 MPH but beefed up suspension and a very expensive aluminum drive shaft is also installed to maintain mechanical integrity of the drive train…The HPP Vics (the ones with dual exhausts) have the HO engine but speed is limited to 118 mph to protect the driveline…

The extra horsepower from the “HO” engine is actually pretty much exclusively derived from the free-flowing exhaust.

And MikeInNH, you are correct. Rather than programming, the term should be calibration. That’s the term that Ford uses, anyway.

You’ve been given good advice but my question is this.
You appear to be wanting a car to run more conservatively. Why do you want to de-tune it?

Nit picking, eh? Consider the way the term programming is commonly used. It can mean the code that executes on the microprocessor. i.e. program instructions. It is also used to describe the process of storing the binary object onto the FLASH memory in the microprocessor. In that vein, the person is reprogramming the microprocessor. It has no distinction between static constants versus executable code. A third interpretation is that the static constants and the executable are recompiled and bound together at link time. So it that case, the “program” as a whole has changed and is downloaded as single unit. Therefore, the programming has indeed changed.

In a purist sense, you’re correct. But that’s like the argument between the use of engine and motor…

My take on this is based on the recent trend I see in people who think they can do better than the factory programming and increase mileage. It’s possible but like everyhting in life, there is no free lunch. Add to that a thing I like to call “the law of unintended consequences”.