So I was doing 160mph on the Autobahn and got the restricted performance warning and the check engine light started flashing and the car slowed to 90mph and wouldnt go any faster. I got off the Autobahn turned the car off and back on and everything worked fine but its at the dealers now just to be sure. Has this happened to anybody and does anybody know what sensors cause the restricted performance warning to come on in the first place?

 

Holy cow. 160 on the Autobahn. A dream come true.

How'd she handle?

I hope your car is ok, though.

 

She handles pretty good. The Autobahn for the most part is built for high speeds. You can take most curves around that speed just because they are designed that way. Actually 160 has become a non-event because it happens so much I wish one the speedo went to 200 and that the limiter was higher. I think they should have made the top speed higher on the SC and SS models because Germany have so many cars that can go faster. I mean we are good until a AMG or RS badge shows up then it's game over.

 

I'm so jealous.

Those of us in the States will never get to take our cars to that speed (or, if we do, risk immediate license revocation for the pleasure).

It's sad, because there are plenty of roads around here that could handle that kind of speed (Florida Turnpike is like a dream for this, great visibility, straight as an arrow, flat as a pancake)..

 

Yeah the last time I was in the States I had a hard time keeping the rental car under 80. I can't imagine now making a state to state trip doing 75. That would kill me.

 

Is "restricted performance" just a speed limiter? Can it be defeated? The specs online for the SC and SS do say "top speed (mph) 155 limited". I know most motorcycles are limited to 180MPH by agreement of the manufacturers, but there is usually a way to get around this. Bummer for the Autobahn!

 

No restricted performance is when some sensor read something wrong in the engine.

 

US has a lot of space where very nice autobahns could be built. But then they would have to overhaul the whole DMV system to really teach people how to drive because I have to tell you... the average American should be imposed a speed limit of 25mph because the skills are close to zero. And if you flash the high beams behind a stupid slow car on the left lane OOOOOOOHHHHH that's an offense! Give me break.

Autobahns in US will happen when the cup holders are scrapped off all new car designs. = NEVER going to happen. Injury lawyers would love autobahns here though LOL.

I'm happy for you that can drive at 160. I visited Germany a couple of times and rented some fast cars there and it was a lot of fun.

I hope your car is ok.

 

The fact that it happened to you around 155 MPH makes me think that it is a purpose-built sensor of some sort used to limit speed per the specs. Might cut ignition or fuel temporarily like traction control does if you go over the limit. Would be interesting to know what the dealer says.

 

Yeah I am waiting for them to get back to me. I don't think its that because I have been 160mph quite a few times for a sustained period of time. And what I like about the speed limiter(if there is anything to like) is that it's not like a govenor which cuts the power and you feel the power loss. This car just gets to 160mph and stays there. But again at 160mph gas isn't lasting that long. Lol

 

It's a pleasant surprise if and when it happens, but I don't think any of us got this car for great gas mileage!

 

I had the RP problem show up in my XKR when climbing hills at 70 mph. I found a blown fuse on my intercooler aux. pump---not sure where it may be on your XJL.
I found out that my I/C pump was not working and ended up replacing it.
Good Luck,

 

Well it came down to the wrong gas. Germany is pushing E10 gas and the place I normally go only has E10 and Super. I guess the Super is not high enough octane and that's what caused it. On post they still have Super Plus which is 93 percent Octane so now I just have to concerned which Esso stations I go to.

 

I'm glad it wasn't something more serious.

I'm glad I only feed mine 93 octane, even if it'll never see 160 mph.