General Question

Dr_C's avatar

Performance enhancing chips. Good or bad?

Asked by Dr_C (14334points) February 16th, 2010

I was browsing e-bay and found this performance enhancing chip for my Xterra that promises to enhance horsepower and improve gas mileage up to 40 MPG. Does anyone have any experience with these things? Is this really possible? Is it a scam? Will it mess up my car? Should I do it or just move on?

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20 Answers

erichw1504's avatar

Sounds like a scam, but I’ve never had any experience with them. I would check out any reviews you can find on-line about it. Doing any work on your own car is risky, unless you know what you’re doing.

With all the recent sex questions on here, I almost thought you were talking about something else.

Dr_C's avatar

@erichw1504 lol… there have been a lot of sex questions. As far as doing the work myself that’s not an issue. I would most likely take it in to the nearest performance shop. I just figure getting the part myself would be cheaper.

stranger_in_a_strange_land's avatar

You might improve power a bit but it’s unlikely that fuel economy will increase as well. Those claims seem unrealistic.

CMaz's avatar

It works. To an extent. But yes @stranger_in_a_strange_land is right. It will mostly bring up power. And, void the warranty.

njnyjobs's avatar

Maybe it has a fine print somewhere that reads: while going downhill . . .

MrGV's avatar

Don’t buy it; it’s a scam.

CyanoticWasp's avatar

I think to expound on what @ChazMaz says: “it might ‘work’ ... to an extent”.

For example, your computer itself (the one you’re using right now to read this) can be “overclocked” to perform at higher than the manufacturer’s rated speed and capacity. It might even work, and who knows for how long? Maybe even indefinitely. The point is that by overclocking you have now accepted total responsibility for performance, too. If something goes wrong, then you have to explain what you have done to modify the performance parameters, and you may find out that the thing is ruined.

For the investment you make in a computer (these days, anyway), that might not break the bank. But if you force your car engine to “overperform” outside its specifications, then you will 1) have no more warranty, and 2) probably have to work hand in glove with your mechanic so that he knows exactly what is now going on with the vehicle (since the service bulletins and specs that the auto manufacturer publish may now be meaningless in your case) and 3) if things go seriously wrong then you’re looking at a new engine or vehicle.

When you sell the thing then you also incur an obligation to inform the new or prospective buyer that “this isn’t exactly what the manufacturer intended”. Maybe he thinks that’s a good thing, or maybe not. But you have the obligation and risk.

You feeling lucky?

FireMadeFlesh's avatar

The engineers at the factory program the engine to work at a relatively relaxed pace so it is more reliable and to compensate for drivers who don’t look after their cars properly. A performance chip can release more power, and it can increase economy in some cases, but it makes the car more highly strung and potentially less reliable because it places more stress on the components. I would not recommend it unless you’re planning to race, and therefore service the car more regularly.

Dr_C's avatar

Ladies and gentlemen.. the nay’s have it. I will not be purchasing the chip. Done and done.

jerv's avatar

Wish I had seen this earlier, but you made the right decision anyways.

While it’s possible for a chip to improve horsepower, a chip alone won’t really do anything good for your MPG. One thing that does work (at least in my experience) is a little work on the intake side.
Even a simple drop-in K&N filter in the stock airbox makes the engine a little less asthmatic. Whether you use that to get more power or more MPG through reduced pumping losses is up to you. Be warned though, the gains are pretty modest; around 2% or so. A full cold-air intake gets about 5%, but paying six times the cost of a drop-in filter for something only twice as effective isn’t really cost-effective, at least not when you consider that the gain in your case would be less than 1MPG.

What I have found to be the biggest factors in fuel economy are:
1) Vehicle condition – My ‘85 Toyota averaged ~20 MPG when I first got it. After changing the plugs and oil, it went up to ~22, or about 10%.

2) Tire pressure – Affects rolling resistance. Personally, my driving style is such that if I don’t inflate the tires to about 6PSI over factory specs (not to exceed the maximum recommended by the tiremaker though!) then I wear the edges more than the middle, especially on the front; a textbook sign of underinflation. However, the added pressure has a bonus side-effect of better MPG.

3) Driving style – It should go without saying that jackasses who treat every green-light like a drag-launch get poor MPG. Smooth, steady acceleration is more fuel-efficient.
However, depending on the vehicle, you might actually get better MPG at higher speeds, so those people who recommend doing 45 MPH on the freeway are largely full of it. Many of my vehicles have achieved better MPG at 60 MPH than at 50 MPH along the same route under the same conditions, so going slow isn’t the answer. However, letting off the gas a bit sooner and coasting to a stop sign/red light helps quite a bit, and you should have enough momentum to conserve speed well enough to not piss off the people behind you.
Some automatic transmissions are also set up in such a way that you can go the same speed with less pressure on the gas pedal. My old Aerostar was particularly “sloppy” this way, and once I learned the feel of it, I went from 15MPG to ~23.5 without driving any slower. Granted, most of the other slushboxes I’ve driven only picked up another 1–2MPG that way, but every little bit helps, and there is a slim chance that yout Xterra might be as generous as that old van of mine.

4) Constriction in the intake and/or exhaust system – The harder it is to get air in and out of the engine, the more energy from the burnt fuel goes into pumping air which means less energy to move the vehicle. many of the mods made to performance engines can also help MPG if you keep your foot out of it because they work to reduce these “pumping losses”. Try breathing deeply through a soda straw and you’ll see how that works.
Unfortunately, those same mods tend to make some people drive like jackasses, so it takes a little discipline for this route to efficiency to actually work.

Nowhere in there is there any mention of the chip, and there is a reason for that. The stock chip in most cars is calibrated to maintain the most efficient fuel/air ratio and ignition timing possible without hurting the engine. Sure, you could make it run a leaner mixture, but that would likely also make it run hot enough to have serious effects on engine longevity. I think it’s worth a minor MPG hit to extend the life of the engine at least tenfold; I am not a fan of replacing burnt valves or otherwise rebuilding an engine every few months.

Chips alone won’t do it, and anything that claims to increase your MPG more than about 5% is highly suspect.

lillycoyote's avatar

I’m against them but I fully support the use of performance enhancing Nacho Cheese Doritos and a couple of cold bottles of beer.

TheJoker's avatar

Only if they’re served with performance enhancing fish… & a sprinkle of salt’n’vinegar.

RocketGuy's avatar

I added a K&N style ram air intake to my Integra. I can get 10% better MPG or 10% better power, depending on how hard I press on the gas pedal. So I agree with that part of @jerv comments.

I also agree that the chip is designed for most efficient fuel/air ratio. I don’t see how a chip can increase both MPG and power, though.

jerv's avatar

To add on:

There is only so much potential chemical energy in fuel that can be turned into mechanical energy. The only way to increase both power and fuel economy is to be more efficient in converting that energy.
Well, there is little that can be done about the waste heat, and that is where a LARGE chunk of the energy in a normal internal combustion engine goes. If you beg to differ then explain why the difference in temperature between your fuel tank and your exhaust is so huge, and why the engine needs such a massive cooling system to keep from melting.
There are ways to make the engine more efficient, but none of them can be done with a chip alone. For instance, carburetors suck at efficiency since the atomized fuel re-condenses before it hits the combustion chamber. TBI (Throttle Body Injection) isn’t much better. To show you what a difference in makes, look at the old Saturns. The ‘94 SOHC models had 85 HP and got ~26 MPG in real-world driving. The 95+ SOHC models went to MPFI (Multi-Port Fuel Injection; what most cars today use) and got a bump to 100 HP and ~28 MPG with the same bore, stroke, compression ratio, etcetera.
Big boost in both numbers, but it took more than a chip to do it.

As it stands though, major car makers do everything they can to eke out as much energy from each gallon as they can without increasing their manufacturing or R&D costs, so engines run already as efficiently as they can without costing BIG money. Plus, engines are inherently inefficient anyways, wasting >70% of the energy of the gas you put into them. Even the expensive racing/performance engines are only marginally more efficient than the engine in, say, a Corolla. Why do you think Dodge Vipers only get about 10 MPG?
At full speed, the Bugatti Veyron can drain it’s tanks in 12 minutes (~3MPG, or ~1.4 gallons per minute) and I am pretty sure that they pulled every trick in the book (and wrote a few new ones) to make that 1001 HP. There is also a reason that it has 10 (ten) radiators, four of them for the engine alone.


ApolloX64's avatar

The “chips” advertised on eBay are actually just a plug ‘n play module that overrides the ECM’s fuel/air mix ratios. They actually cause a lot of harm and will more than likely ruin injectors and Mass Air Flow sensors. They will also cause your ECM to think it is having issues and cause several codes to come up causing the ECM to overcompensate in some areas and under-compensate in others. Causing your engine to run too rich which will destroy your catalytic converter and O2 sensors, or too lean which will ruin your spark plugs, piston rings and eventually cylinder walls.
The only way to “enhance” your ECM without ruining everything is to send it to a company like JetChips. They then go over a list of engine modifications (REAL MODS, like an added turbo, bigger injectors, higher output ignition system, dual exhaust etc etc) and fine tune your current ECM to take advantage of the new systems PROPERLY. This kind of tuning is only needed when you do a mass amount of modifications. Most ECMs can handle an engine that has a turbo added on, however you will need a re-program if you do a turbo, dual exhaust and bigger injectors.
Also, a re-program is done on a vehicle specific basis with data collected from the driver on account of installed mods, whereas cheap plug ‘n play add on chips are generic and do not actually take into account the many hundreds of thousands of variables between different makes and models.

My 2 cents from several years of experience. Enjoy. :P

jerv's avatar

@ApolloX64 Agreed.
The chips I trust are the ones that you can reprogram yourself with a laptop. Of course, doing it right takes a bit of time and skill or a bit of cash in the hands of people who actually have the skills.

ApolloX64's avatar

And of course, there is alway my favorite rule “There’s no replacement for displacement.” :P

Computer controls, Multi-Port Fuel Injection and Cold Air kits are fun and all, but I’ll stick with my nice classic mechanical, flat tappet, carburetor fed 400 ci monstrosity for my kicks.

jerv's avatar

@ApolloX64 So long as they don’t make the car too nose-heavy and make it understeer like a pregnant ox. There is more to life than ETs :P

Granted, computer controls and fuel injection allow for a car that an be started and run under a wide variety of weather conditions (something I al all too aware of with my old ‘yota) and allows for more power due to better fuel atomization (and diesels have been doing Direct Injection for decades) but sometimes you just need to here a rumble instead of a wastegate whoosh.

SecondHandStoke's avatar

More info is needed.

Some are next to worthless, others make a profound difference.

SecondHandStoke's avatar

These are no joke.

Dinan knows what the hell they’re doing, the only BMW tuner available through BMW dealerships.

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