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I just bought a 2006 kia rio sedan with a manual 5 speed transmission. During the test drive I couldn't go over 55mph (wasn't near any freeways)

My first time on the freeway the rpms were around 3300 at 65 mph and the car sounded like it needed to shift to another gear, but there's obviously not another. Is this normal? If so, a long trip at 70 mph wouldn't be pleasant.

I obviously don't want to damage anything. I've only owned one small 4 cyl car before and it was an automatic. I'm stressed out because I've already spent more in repairs than I wanted to and will really be bummed if there's a issue with the transmission.

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    You had changed to 5th... this is normal for small engines they nedd higher revs to develop power. But have you checked the tire sizes? Smaller diameters increase engine speed. Bigger cars are built for cruising, smaller ones for running about town ie « shopping trolleys » - consider which one you need, my car is about 2000rpm at 80mph...
    – Solar Mike
    Nov 16, 2019 at 7:04
  • How high did the automatic rev, or don't you know?
    – Harper - Reinstate Monica
    Nov 16, 2019 at 15:33
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    I have seen 3000rpm on the highway, but without the engine sounding excessively loud. Unrelated, but am I the only one that doesn't like the standard abbreviation for "transmission"?
    – Michael
    Nov 16, 2019 at 23:03
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    This is completely normal for a 4 cylinder engine.
    – R.. GitHub STOP HELPING ICE
    Nov 17, 2019 at 2:40
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    On my old (2003) Fiesta, I noted that both dials on the dash used to hit the 12 o'clock position simultaneously: 70mph and 3500rpm. I loved that old car, but it was largely impossible to hold a conversation at normal volume when driving down the motorway. Nothing wrong with it, just loud.
    – anaximander
    Nov 18, 2019 at 10:27

3 Answers 3

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The specs for this vehicle show that it has a 5-speed manual and that 5th gear is OD/Overdrive. According to the performance data here:

Kia Rio Gear Ratios

The following table from that page lists the speed at 1000 rpm for each gear:

1000rpm speed:     (km/h/mph)
I:                  7.7 / 4.8
II:                13.6 / 8.5
III:              20.4 / 12.7
IV:               27.1 / 16.8
V:                33.3 / 20.7

So in 5th gear the you should get 20.7 mph in 5th gear at 1000 rpm. Scaling this to 65 mph (multiplying both values by 3.14 or the ratio of 65 mph/20.7 mph) gives a predicted rpm of 3140. That's in line with what you read as 3300 rpm.

So yes, that seems to be the normal rpm at 65 mph. Your rpm could be a bit high due to an inaccurate speedometer or tires a size or two smaller than the tires on the test car.

That engine speed does not seem unusually high for such a car.

Note: I edited the to include the image from the page rather than the link as it is the results of a search and is not a direct link.

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    That link appears to be for a BMW.
    – Harper - Reinstate Monica
    Nov 16, 2019 at 15:39
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    Even so, 3100rpm will not be an unusual highway cruise speed for a second-generation Ro with a fairly small motor.
    – DavidRecallsMonica
    Nov 16, 2019 at 15:56
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    3000 - 3500 RPM wouldn't be unusual for any car with a 1.0 to 1.4 liter engine, IMO. For the Kia specifically, except for the 1.0 T-GDi ISG engine, max power is at 6000 RPM and max torque at 4000.
    – alephzero
    Nov 16, 2019 at 21:27
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    Tyre size wouldn't change the ratio of RPM to indicated speed unless the speedo is not mechanical (eg GPS or something), smaller wheels would mean you are moving slower at a particular rpm but the speedo would be reading high
    – Dave Smith
    Nov 18, 2019 at 13:38
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That is the excellent Mazda B3 engine. It will give you 300k service if you treat it nicely. It loves to rev. It does not like to lug.

If you are at high power at low RPM (e.g. an RPM that feels right for an American V8) and you start hearing what sounds like tappet noise, that is actually the main bearings bottoming out metal on metal. Stop that instantly and downshift.

It really loves to rev. I doubt you could damage the engine at any (high) RPM you would dare put on it. Obviously, don't run it past redline, but the ignition system won't let you do that; it will shut off spark and/or fuel at that point.

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    Darn you, AutoCorrect!
    – Harper - Reinstate Monica
    Nov 17, 2019 at 21:00
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    "Excellent engine" - "main bearings bottoming out"
    – towe
    Nov 18, 2019 at 9:51
  • @towe: Run any engine well out of its design-spec envelope and you'll see it suffer. That doesn't say anything about whether it's a good or bad engine for what it was designed to do.
    – DevSolar
    Nov 18, 2019 at 12:14
  • @DevSolar Nothing between idle speed and the redline should harm an "excellent" engine.
    – towe
    Nov 18, 2019 at 13:30
  • @towe: I think that you will find most engines taking a dim view on being put under load at just above idle.
    – DevSolar
    Nov 18, 2019 at 14:37
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I got 3,000 rpm at 120 km/h on a Hyunday Grand i10, 1.2 lts engine (~5 lts/100km)

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  • Yup, on 1-1.4 litre cars, going 3k rpm and over is quite normal on the highway/freeway. My car runs 4k at 140 km/h (kph, 87 mph). It can do that for a long, long time without problems. Might wear down a bit faster, but nothing major.
    – Mast
    Nov 17, 2019 at 13:12

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