Computer chips



We have a 2008 Toyota Tundra, 5.7 V8 that we really appreciate. However, the gas mileage is lousy unless I drive conservatively (Generally around 19) and if we’re not pulling our 6500 5th wheel. I was wondering if anyone has tried aftermarket computer chips. Advertisements for these products indicate increased mileage and power and any increase would be appreciated.


Ask yourself - if a cheap add on would increase the power and economy of your vehicle, why wouldn’t the factory have done it already? Answer is, they would have.

99% of these are worthless scams. The only way to do the is to reprogram (not ‘chip’) the engine control computer, typically with the use of a laptop and an dynamometer. Not some $99 ‘chip’ they sell for every vehicle under the sun.


I have a handheld tuner for my 300C with the “Hemi” I picked it up off ebay–it was more than $99. I’m kind of a gearhead or I wouldn’t be on this site. I bought it not for blistering performance, but more to tinker with.

The tuner lets me do a lot of little tweaks–I am running a “91 octane tune” right now which I estimate gives me about 20 more HP and improves responsiveness. (I have to use 91 octane gas, as the name implies) I also can adjust the shift firmness of my transmission (I like it firmer) and adjust dozens of other things including when the cooling fans come on, at what RPM the transmission shifts, and do things that can get me in real trouble like deactivating the rev limiter and auto-upshift when using the transmission in “autostick” mode. And many more. There are also performance options like “dyno mode”, and if you know what you’re doing you can adjust the ignition timing advance across the entire RPM range. You can also adjust for different tire size/speedometer calibration, and different final drive ratio. If that’s not enough, you can download customized tunes from the vendor for your vehicle. The tuner also acts as a scan tool allowing you to read any stored trouble codes including pending ones, clear them, and will log data from the engine’s sensors in real time.

An unexpected side effect of increasing the performance is that I get SLIGHTLY better gas mileage. (offset by using gas that is 10¢ more) I don’t know what this is doing to my emissions because I live in a state that doesn’t test. (there are CA emissions versions of the various performance tunes too)

A crappy $99 “chip” is likely to be just a simple resistor that you can buy at Radio Shack that fools the computer into thinking the engine is cold all the time so it richens the fuel mixture. More fuel=less gas mileage=more carbon in your engine=possibly damaging your engine or catalytic converter over time. And your check engine light will likely be on constantly.

I have no warranty on my vehicle and am conservative with what I’m willing to adjust. I have had no ill effects using the handheld tuner–indeed I expect firmer shifts are better for the transmission than soft “luxury” ones. If you have any warranty left I would not consider using a tuner until it is up. You will instantly void the warranty if the dealer finds out you are using one of these. There was a post a year or so ago from someone with a diesel (F250?) who used a tuner on his or her truck and destroyed the engine, so something to think about. I don’t know what’s available for your vehicle, but I’m sure there’s a Tundra board on the web somewhere that can advise you if you choose to go this route.


When did 19mpg in a full-size truck with (I assume 4WD) and a V8 engine become “lousy.”

If it will adequately pull your 6500# 5th wheel you’ve got plenty of power and the price for that is fuel economy. I doubt any aftermarket devices will get you much more mileage. In my opinion 19mpg is pretty darn good.


You can’t have both increased power and better fuel economy and still meet exhaust emissions. Not going to happen. I agree with @texases that the majority of these “chips” are scams. I also agree with @asemaster.

Advertisements for these products indicate increased mileage and power and any increase would be appreciated.

All they do is succeed is to separate people from their hard earned money. Oh…it’s a computer chip - it MUST be good.

The computer chip that these companies sell is basically a list of values that are read by the ECU (the CPU and imbedded software). The values tell the ECU to do certain things (like apply more gas) when the readings from one of the sensors reaches the values in the chip. The chip just has a new set of values to work of off. It’s extremely low tech. But their advertising makes people think it’s this real sophisticated peace of engineering.

As texas said…if it would work…then every manufacturer in the world be doing it. It would take a junior engineer about an hour to build the table.


I think the ECM computer chips – or reprogramming the existing one – could provide some improvement, but only to one or the other function, not to both. Improve mpg at the expense of acceleration, or improve acceleration at the expense of mpg. If what you want is improved mpg, a new chip or reprogramming could probably do it, but you could do the same thing yourself by minor changes in driving habits. You could Google “hypermiling” for some ideas. Save you the expense of new chips or reprogramming.


We’ve discussed this before, and some do not agree with me on this, but you can improve both mpg and power if you’re willing to ignore exhaust emissions. Automakers are mandated by both exhaust emission levels and that they can only use a stoichiometric correct air/fuel ratio. Making the mixture slightly richer will improve both power and mpg.


From some of the reviews I’ve found for the Hypertech (which cost’s alot more than $99) but generally has a god reputation, is that you might gain 2-3mpg. A cold air Intake or free-flowing exhaust have a slightly better shot at increasing mileage.

Someone else has asked about hypertech on tundrasolutions a few days ago with no response yet.


19 mpg in a Tundra?,no wonder no one around here buys one with the smaller engines. Back in the day 8-9mpg was the expected mpg from a chevy with a carburated 5.7,with full time 4wd,then along came the TBI 5.7,getting around 13 mpg,then the current series of small blocks(5.3) gettimg around 16-17 mpg. Dont mess with perfection,you want fairly decent economy and power pulling a trailer?,get a Duramax.
Dont waste your money on a CAI or exhaust mods(been there,done that){I’m now from the Lingenfelter school of exhaust tech) unless you have endless funds and like racket.I used to be happy with tinbox F-100s (V-8) getting 13 mpg-no Auto,no PS,no nothing-Kevin

From some of the reviews I've found for the Hypertech (which cost's alot more than $99) but generally has a god reputation, is that you might gain 2-3mpg. A cold air Intake or free-flowing exhaust have a slightly better shot at increasing mileage.

You do know that companies will PAY you to write a good review about their product. It’s all through 3rd parties…and it’s really back door. But it’s out there…and has been going on ever since reviews in the internet have been written.


Considering that the 2008 Tundra with the 5.7L is rated for 14-16 MPG overall. 19 MPG is actually outstanding. Be thankful that you’re getting that.


Sounds like the vehicle is working perfectly for the purpose you intended. I wouldn’t mess with the fuel metering…which is what a chip will do (if anything), possibly in a way that you’ll regret. This vehicle isn’t designed for economy. It’s designed for hauling 6500 pound 5th wheel trailers.