Let’s assume you have a long stretch of highway, with a level grade, in good weather with lots of visibility. Let’s also say that there is no police presence, hence no chance of getting busted for speeding. How fast do you travel on this road?
For me, it’s 85mph, maybe up to 90 if I have to pass someone.
I’ll admit to 120 but it was on a seldom patrolled narrow backroad with almost no traffic and I was on a motorcycle.
Today, I generally drive under the speed limit because if I go faster, my car burns too much gas and also, there is a big difference between going 70 miles per hour and actually being someplace 70 miles away one hour from now. Speeding adds so much to the cost of driving and gives very little in time saved. It takes me about 50 minutes to make my 38 mile trip home from work even though it is almost all highway and I am going 60mph or more for most of the distance, but not for most of the time.
With age comes wisdom–or at least with age comes more conservative driving, IMHO.
In my younger days, I did get a couple of cars up to 90 or 95 mph for brief spurts, and it was definitely fun. However, an aversion to getting a speeding ticket has kept me from such stunts for many years now. And, as B.L.E. stated, the quest for decent gas mileage helps most of us to keep our speeds down nowadays.
At this point in my life, I will take my car up to 75 when necessary for a very brief passing spurt on an interstate highway/expressway. But, in more typical driving situations, I tend to keep my cruise control set for about 3 or 4 mph over the speed limit.
It depends on the vehicle, the conditions, and the road. For normal highways with 75 mph speed limits, I’m usually pretty comfortable in the 75-85 mph range where most of the traffic is driving (there’s not much point in driving faster than the traffic flow). I don’t think I’ve had a car/motorcycle over 100 for about a decade. OTOH, I have a jeep that is scary at about 75.
Driving fast on the street isn’t any fun anyway, sign up for a driving school and try it on a road course with a good car or bike.
I don’t go over 75 even if I’m the only one on long stretch of highway. Usually I’m around 70. And in NE that means I’m usually in the right lane as I get passed by almost everyone.
My 98 Civic has reached 105 MPH on an abandoned airport runway. That may be what led to the cracked exhaust manifold.
I’ve had a friend’s Toyota Supra up to 145mph on the highway and my old Grand Prix up to 110mph. Those were both 15+ years ago in my “not so wise” days. Now its usually 10 over the limit.
82 to 85. max of 90 (usually from inattention) havent gone 100 in a decade or so. havent gone well over 100 in 25 years … maybe 30. been a while. but no tickets, no accidents, and no reason to die young (er, ish, ever)
Back in my tournament fishing days I’ve pulled boats over 95 mph but fuel’s too expensive today. I ran 80 on the interstate until fuel hit $4.00 a gallon and run under 70 most of the time.
Skipper
I got a Hyundai Accent up to 140km/h on a stretch of Highway 1 in Saskatchewan (where you can see the cops three hours ahead of you, and there’s no curves in the road for about 500 km.) I probably would have gone faster, but the Accent wasn’t powerful enough. Plus, it had about 600lbs of stuff in the car at the time.
Agree, it depends what you are driving and where. The fastest I drove in the US for any distance was 90 mph across the Bonneville Salt Flats in a 1964 Buick Riviera, the summer of 1964. It was brutally hot with the landscape shimmering like a mirage. The first stop was Andover Nevada with a roadhouse that served ice cold beer. My gas mileage was a miserable 14 mpg.
Overseas I drove a steady 100 mph non-stop from Frankfurt, Germany to the Dutch border on E3, a 6 lane autobahn. Since many drivers were going faster, this 200 mile+ trip seemed rather leasurely.
Nowadays, I try for a balance between gas mileage, fatigue, and the value of time. This means about 75mph on most Interstates.
My usual highway speed is 3-4 mph above the posted limit which is as fast as I think I can go without significant risk of a speeding ticket. Even if I don’t have to worry about a ticket, an accident would bring in the police who would quickly figure out how fast I was going.
A less hypothetical question would be, “How fast would you drive on a closed highway?” Examples are the “races” on Nevada highways formally closed for those events. Since I wouldn’t have to worry about access by the general public or police investigation of an accident, I would go as fast as my car and my abilities permitted. That would be 150 mph.
about 120 MPH, provided I’m the only car on the road. Otherwise I would just maintain the prevailing speed.
In my misspent youth I owned a Harley Sportster and often drove it to the limit for miles. Above about 80 mph the speedometer couldn’t be watched. I’m lucky to have survived.
On an interstate with a posted speed of 70 I may do 80 at times.
The fastest I’ve been on a deserted stretch of interstate was a shade over a 125 in a '68 Plymouth Roadrunner and about 115 in a '59 Corvette (not too shabby considering the 4:11 gear ratio).
Pay attention to the speed rating on your tires. Maybe this would be the last thing to check.
I lived in France for a while back in the early '90s. I once took my motorcycle on the Autobahn in Germany and ran it above 100MPH for just over an hour. I then needed fuel. Turns out it uses fuel faster at those speeds 
That was just a one time deal just to say I did it. Normally, depending on the highway and traffic I typically ran 80 to 95 MPH on the European highways with my motorcycle, and about 85 to 90 MPH with the Citroen. It just wouldn’t do much more.
On US highways I stay with 10MPH over whatever is posted. Any more than that and you are really getting out of the flow-of-traffic speed. I did once make a 90 to 95 MPH run across South Dakota trying (sucessfully) to outrun a rainstorm on the motorcycle. I wasn’t really going much above normal traffic flow at the time.
If I could take my car (V6 Accord) to the Autobahn I don’t know what I’d find comfortable on the no-speed-limit sections, but I suspect it would be in triple digits.
Being a law-abiding inhabitant of this space-time continuum, I never exceed the speed of light. ;-}
70-75. Faster is too hard on the car plus there are too many things that can happen such as road debris, animals, and so on that make faster speeds fool hardy.
I’ve been up to about 105 a number of times when passing…but I’m getting better now. I zip up over 90 often when passing.
In my current car it’s easy. I remember having my '89 Toyota pickup over 80 once and it was like “Mr. Toad’s Wild Ride”. If I had a 911 I’d be in serious trouble.