Let’s start off by saying the Jeep Wrangler and speed should never be used in the same sentence. With that being said, many Wrangler owners would appreciate a little extra oomph, especially those who have fitted bigger tires and some extra kit. So, what and why is the Wrangler limited, and can the limiter be disabled?
The Rubicon ECU limits the top speed to 97mph and the Sport to 115mph. Top speed is regulated due to the Q speed rated tires which have a speed limit of 100mph.
My question is, why anyone in their right mind would want to drive a Wrangler over 97 mph, it’s beyond me. The Wrangler has arguably one of the worst aerodynamics and coupled with a high center of gravity and solid front and rear axles don’t exactly make it the most stable vehicle at high speed either.
But let’s for argument’s sake say you fit higher speed-rated HT tires with bigger rims for extra stability, what is the maximum speed you can squeeze out of your Wrangler, and what are some important considerations?
Let’s find out!
Do jeeps have speed limiters? DISABLED
Yes, Jeep Rubicon’s have a speed limit programmed into the vehicle’s ECU to govern the max speed to 97mph. This is not necessarily the maximum speed the Jeep can go, but it is a safety precaution due to the Q-rated factory tires and other safety regulatory factors.
If you want to go faster than 99 MPH, don’t buy a Wrangler. They were NEVER designed to go fast.
Can you change the tires to go fast?
Option #1 – Jeep Tire Rating
What is the speed rating anyway and why is the Rubicon speed limited as a result thereof?
Well the rating of the tires, simply put, is the fast speed at which the tires are designed to be driven safely. Drive at speeds anything over and above the limited tire speed and you are then operating outside the safety restrictions which has been engineered of the said tire. For example, the chunky, off-road-oriented 33-inch BFGoodrich All-Terrain KO2 tires carry a Q speed rating, which equates to 100 mph.
Auto manufacturers will never allow a vehicle’s top speed to exceed its tires’ speed rating, even if the vehicle is capable to.
This is in place to protect the vehicle manufacturers from liability suits should there be a high-speed tire failure as a result.
Then there’s the “death wobble”…
Option #2 – Jeep Death Wobble
The dreaded death wobble is another factor you need to consider when driving at high speeds with your wrangler. Given, that most wrangler owners have and never will experience this scary phenomenon, however, it’s still something to keep in mind even though most report it to be excessive between 45-60mph (64-96km/h) but seems to go away after 70mph (112km/h). Throw a set of oversized knobblies and things can get out of control sooner rather than later.
In most cases, it is worn-out suspension components that are responsible for all sorts of vibrations and wobbles which is never going to be a pleasant experience, by any stretch of the imagination. Be that as it may, any young wheeler will find a way to get onto the trails where he can thrash his Jeep about to his heart’s content. There is absolutely no reason for anyone to be racing at over 97mph just to go off-road and the wrangler is never the type of vehicle you want to do any speed runs in.
The Wrangler has the aerodynamics of a brick, and the turning capabilities of a charging rhino, yet some are comfortable driving it over 97mph
Me, I say, do whatever you are comfortable with, just make sure you are more cautious around others and be responsible. There are people who jump off buildings and out of speeding planes for fun, so to each his own.
Option #3 – Aerodynamics
If you ask any kid to draw a picture of a vehicle, in most cases it strongly resembles the square slab-sided features of a Jeep. With the aerodynamics of a Lego block, driving at speeds anywhere over 85mph is pushing the laws of physics.
With the aerodynamics of a Lego block, driving at speeds anywhere over 85mph is pushing the laws of physics
One just has to look at vehicles designed to go fast. They share absolutely no attributes with the Wrangler at all. Sports cars are usually more curvaceous for better aerodynamics, wider, and lower to the ground which equates to a lower center of gravity, offering more stability. This allows them to navigate corners at high speeds without breaking a sweat.
The Jeep brick, not so much!
Option #4 – ECU Limits
The top speed of the Jeep is limited by an electronic governor which is programmed into the engine ECU. Every vehicle is equipped with one for safety reasons. The ECU limits top speed as a safety regulation and is different from vehicle to vehicle depending on the speed rating of the tires the vehicle is equipped with from the factory.
Can it be tuned out? Of course, everything man-made can be modified!
Can You Disable the Jeep Speed Limiter?
There are tuning companies that will happily tune your Jeeps speed limiter for higher top speeds. There are handheld tuners available that allow you to do this by manipulating the factory ECU settings at the flick of a button. In most cases, there are a few pre-defined top-speed options to choose from
If you are hell-bent on going fast with your Wrangler, It comes highly recommended to upgrade your wheel size and tires first. Pock up a set of 20s with more road-oriented tires which will immediately improve stability and safety at higher speeds.
If you are hell-bent on going fast with your Wrangler, It comes highly recommended to upgrade your wheel size and tires first.
There are tuners such as Livernois who can get a tune made up for you.
They already unlock JL ECUs and have tunes for dodge 5.7 v8.
Gains of up to 61WHP and 48WTQ on 5.7
WATCH – SX V8 Swapped Jeep Wrangler Obliterates 40″ Tires!
How Much Boost Can A 3.6 Pentastar Handle (Power Upgrades)
If you’re interested in increasing the BHP on your Pentastar then this article is for you. Many have enquired and are interested in increasing the 3.6 Pentastar in the form of a bolt-on Turbo or Supercharger kit to squeeze some extra ponies out of this lump. So what are your options and what is a safe amount of boost you can expect on the 3.6 Pentastar without forfeiting your reliability?
Many reputable performance shops that offer these upgrades all agreed that 10 to 12lbs is a safe zone without decreasing reliability. Once you push it over 14lbs you run the risk of suffering catastrophic cooling and head failure.
Click the link below to read more…
Jeep Owner’s Feedback/Experiences
Let’s look at a few Jeep Owner’s real-life experiences with speed limits
Feedback/Experiences
I’m fairly sure that safety goes out the window at 99mph. And…the engine pushing it makes absolutely no difference whatsoever. Hopefully, we won’t see any 392s in the Cars & Coffee crash videos, but the good news is that the 392, with its ground clearance, will fare better than most when it jumps the curb after losing control.
https://www.jlwranglerforums.com/forum/threads/392-hacking-the-99-miles-per-hour-limit.69947/
Feedback/Experiences
Make sure your tires are rated for those speeds, such as BFG TA TO2 are rated for 99MPH. Tire speed ratings are why there’s a governor, to begin with. “Bigger more comfortable tires” has absolutely nothing to do with how fast they are rated for.
https://www.jlwranglerforums.com/forum/threads/disable-97mph-top-speed-governor-due-to-stock-33-m-t.54593/
Feedback/Experiences
If just want higher end. Use your favorite brand programmer and program as tall a tire as it can. Sure your Speedo will be off. Use a GPS to see your top speed. Now granted, that has the possibility of creating mayfly tires. But just engineering speaking it should work. I know the computer uses tire size to calculate speed.
https://www.jlwranglerforums.com/forum/threads/392-hacking-the-99-miles-per-hour-limit.69947/page-3
I myself don’t recommend any modifications or speeding!
Resources
https://www.jlwranglerforums.com/forum/threads/392-hacking-the-99-miles-per-hour-limit.69947/
https://www.jlwranglerforums.com/forum/threads/392-hacking-the-99-miles-per-hour-limit.69947/page-3
Conclusion
Anyone who wants to bypass this and travel faster than 97mph on a Rubicon bought the wrong vehicle.