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I'm running a manual Opel Corsa 2005 Sedan (engine code: C16SE, 1600cc). The problem I'm encountering is that the car won't reach its maximum speed of 200km/h as similar cars do. Instead, it stops accelerating at 150km/h no matter what I do even with the gas pedal floored. I have replaced my worn clutch and the new one works great (apart from this problem) so I exclude that. Here are some info and notices that might help:

  • The engine turns on normally and idles just fine
  • Accelerating from zero up to 130km/h is smooth. It is harder to go past that but eventually the car reaches 150km/h (i.e. takes more time to gather speed)
  • During idle, 1st, 2nd, 3rd, and (maybe) 4th gears, the engine RPM can reach 6400 and cut-off as designed. On 5th gear, however, RPM can't exceed 4500. So RPM stops at 4500 plus car speed stops at 150km/h.
  • Gas mileage is fine for that car
  • I'm using the recommended fuel as per the owner's manual
  • Using 10W-40 semi-synthetic oil, suitable for the engine
  • Air-filer was replaced 12 months ago and used for 9,000 km and was cleaned once since then
  • Fuel-filter was replaced 14 months ago and used for 10,000 km. The mechanic have cleaned it once few months ago and it was OK.
  • I sense some misfire even at idling like pulses that I feel them under my feet
  • Sometimes check engine light comes on at speeds between 130-150km/h then turns off when I slow down to below 130km/h
  • Timing belt was replaced 6 months ago and no sign of improper installation
  • Spark plugs last changed since 10,000 km (14 months ago). I also replaced the wires 7 months ago.

What could be the reason for the lack of acceleration bearing in mind the car's behaviour as explained above?

  • Is the car really 2005 with C16SE engine? I'm having some trouble finding information about this engine for a 2005 Corsa. According to Wikipedia, Corsa C has 1.4 litre and 1.8 litre engines but not 1.6 litre. Anyway, 200 km/h from a 100 hp engine may be asking too much. – juhist Apr 22 '18 at 10:33
  • Another data point: my 100 horsepower 2011 Toyota Yaris had maximum speed of 175 km/h... If you have lost some horses, that could explain the poor 150 km/h speed. – juhist Apr 22 '18 at 10:41
  • @juhist I mentioned it is Sedan version (manufactured in Brazil) which is different than the hatchback released in Europe. So yes it is 1.6 litre and generates 101 hp at 6200 RPM. The question because I know people with the same car who can reach 180-190 km/h speeds. Maybe 200km/h is theoretical or in stock conditions but 180-190km/h are realistic speeds for the same car which I can't reach. – Ahmed salah Apr 22 '18 at 10:44
  • @juhist Regarding horsepower loss, so you suggest a compression test. Am I understanding correctly? – Ahmed salah Apr 22 '18 at 10:45
  • Most modern cars use 5W30, 5W20, or even 0W20 motor oil. Using a thicker oil can cause you to lose HP due to the engine having to push it around. Using 10W40 could be robbing your engine of the HP needed to exceed light speed as it seems you'd like to do. – Pᴀᴜʟsᴛᴇʀ2 Apr 22 '18 at 12:51
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I think I have enough data for an answer, so I'll provide it here instead of as comments.

200 km/h from a 100hp engine is way too much. Solar Mike noticed that the particular engine has 186 km/h top speed on an older hatchback. I'm not sure if this is valid for the 2005 sedan, as information about the 2005 sedan is hard to find.

My 100 hp engine in a 2011 Toyota Yaris hatchback resulted in a top speed of 175 km/h. Nowhere near 200 km/h. My 1989 Opel Vectra sedan with 115 hp engine had top speed of 198 km/h, but it was reached on the 4th gear, not on the 5th. Also, the 1989 Opel Vectra was more aerodynamic than most cars.

Based on this, I don't think you'll ever reach 200 km/h on a 100 hp sedan. A very aerodynamic car with 120 hp could reach 200 km/h. A less aerodynamic car (such as a hatchback) will probably require 150 hp.

Your engine may have lost some horses due to its age. The first thing to start investigating the issue would be a compression test. Of course, if you want to be comprehensive, you could measure the engine power on a dynamometer to give more direct power reading and especially the power at high RPMs.

Note also hill grade, outside air temperature (cold air is more dense and thus air resistance is higher) and wind speed and direction when determining the top speed. Additional weight in the car can also slightly lower the top speed.

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Where did you get the max speed of 200km/hr from?

Is it just because it is shown on the speedo?

See wiki description here and it seems it was 186km/h, but with age that will be less - especially if the maintenance was not good... Also, the max speed is usually set with a minimum weight and other conditions...

  • You are right. The 200km/h is a word spreads about this car in my country but I know no one who reached it. I do, however, know people with the same car and age who can reach speeds between 180-190km/h (close to what you mentioned). So it should be capable. Again you are correct about the maintenance as a decisive factor here which is why I'm asking. What should I do to fix it? What maintenance is needed now to restore its full power? – Ahmed salah Apr 22 '18 at 10:49
  • @ solar mike states the obvious; not enough power . There is a small chance it is because of a condition problem. – blacksmith37 Nov 7 at 16:29
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Over time, a lot of top-end components can have a build-up of carbon. This can affect performance to a degree. If you're looking for another simple solution, it might be worth using an Top End Treatment like SeaFoam. A fuel system treatment may also be warranted.

Granted any results from this product will be specific to your situation warranting its use.


There are more advanced tests which can be performed such as Vacuum Tests, Leak-Down Tests, Dry and Wet Compression tests, which will give a more specific picture of the engines health but these might be out of the scope of the query.

Here's a link on how to perform a Vacuum Test

Here's a link on how to perform a Leak-Down Test

Here's a link on how to perform a Dry and Wet Compression Test

Here's a video on how to perform a Compression Test

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If we go just by the speedometer rather than GPS or laser timing rigs, I've had decidedly north of 200km/h from a 106 BHP car (a Megane Sport, which is maybe more aerodynamic than a Corsa but has a larger frontal area/body skin area and more weight) which what sound like similar gear ratios. I think officially it was rated for somewhere in the low 190s, but it could nudge 200 on the clock on the flat and definitely continue past 210 downhill.

In any case, even if the car is only officially rated for 186km/h, not being able to clear 150 is really bad for a 100HP model. That's more like what you'd expect from something with half the power. My first car, a 45HP, 4-speed Polo with the aerodynamic finesse of a brick with a corner chipped off, officially made 145 and could be routinely coaxed to 150+ on the dial (and its higher powered brethren were stated as making, for example, about 155km/h for the 55HP model). I've had or driven 70ish HP Astra, Clio, Punto that were all happiest in the low 160s but could be eked higher and one was known to clear 190. And I've had a brace of 80ish horsepower machines, the slowest of which caps out at 160 dead (GPSed at exactly 155; fwiw, it'll do it in both 4th and 5th, without nearing redline in 4th, which makes me wonder just how horrifically undergeared that supposedly 100HP Corsa is) because for some stupid reason that's what its built in electronic limit nannies it at, even though the official spec says somewhere in the low 170s. The other two could sit at 180 on the dial all day long, varying a bit up and down with gradients.

So the question is, is there an issue with the car's power output, or is it also being limitered out by some kind of electronic cap? It sounds almost like it's only running on two cylinders out of four. But some kind of parental or fleet decision (or even the influence of an insurer's "black box") may be deliberately capping the speed. It's a fairly easy one to determine... we just need some hills. The discrepancy between claimed power and speed is wide enough that the effect should be immediately obvious.

If the car is genuinely only making about 50HP and in need of a mechanic, it'll make 150k on the flat but immediately start losing speed up even a relatively mild hill, and if you point it at some of the steepest to be found on a motorway or autobahn you'll likely have to downshift to save from slowing down too much, and it could well dip noticeably below 130k. Travelling the other way down that same hill you should be able to gather quite a bit of extra speed, maybe exceed 160.

If it's making the advertised power but is being electronically shackled, you'll find it makes almost exactly the same speed on the flat... up any hill up to a certain gradient, after which the speed will only fall off a little (a 100HP machine should still be capable of over 140k on the steepest grades any regular autobahn type road can offer)... and downhill as well, save for any descent steep enough that it will still gather speed without the accelerator being pressed. In which case you'll find that the difference between full throttle, and no throttle, is zero - the pedal has no effect on the car's speed or acceleration at all. If you floor it and push the clutch in, the revs shouldn't rise at all beyond where they would be at 150k... and indeed if you can traverse through that speed, up or down, with the clutch in and accelerator floored, you may see the rev counter move through that point at that speed, on its way to or from idle speed (at any road speed much above 150) vs banging off the limiter (any speed much below it).

In that case, what you need is an electronic exorcist to find and disable the cap ... assuming it's not a condition of your insurance or similar. And if you find some to do that, send them to me so I can unlock the last 15 or so k's out of my bloody Micra...

  • Welcome to the Mechanics Stack Exchange! Great answer here, I agree that this car should be able to go past 150 km/h, even if it takes a while. I do think your answer could be condensed a bit however the information is there so good stuff. – H. Daun Nov 4 at 4:05
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Incidentally, are you sure of those gear ratios, especially of it revving out in 4th?

150k at 4500rpm is 33.3km/h per 1000rpm, a bit short for the power but not uncommon for sportier models. If it revs out at 6400, it'd be doing 213km/h; 200k would be bang on 6000rpm, which I expect is probably the stated max power. The 186k that others mention is more like 5600, which seems a bit low, but may be within the peak power band, or even the stated max depending on how it's tuned.

150k at 6400rpm however is only 23.4km/h per 1000. Last time I saw a 4th gear that low, it was in an oddball 5-speed version of my Polo, or the rather lower powered (75HP) and peakier (all the torque at the top end) "GT" version, neither of which had a 5th gear north of 30k's. It means there's something like a 30% rev drop (or, 42% speed increase) between the top two gears, which is massive... it'd be going some for a 4-speed. It's closer to what third gear is on my lower-powered Micra. Are you entirely certain that's correct? Fancy doing another run and seeing what top speed and rpm it actually reaches in 4th, and reporting back (and, to satisfy my curiosity, what the result is in 3rd).

That could be useful diagnostic info in of itself... if it reaches the exact same speed in 4th and 5th despite very different rpm (and it's close to, but not quite on the redline in 4th)... and indeed if it does it in all three top gears... well, it's not impossible, my old Astra was poorly geared and would go about as fast coming out the top of the power band in 4th as just coming onto it in 5th, but it's unusual. Especially in something with much sportier gearing. It's more likely the product of an electronic limiter. Especially if it then maintains that behaviour up and down hills, which is where you'd expect it to maybe narrow (in terms of revs) downhill but widen uphill.

Also knowing what rpm it supposedly makes max power (and torque) would be helpful here. And if the engine sounds like it's "beating" unevenly, or thump-thumping like a cruiser motorbike.

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