General RPM too high

[cauchemarre]

Hello,

I’ve got the feeling that my RPMs are way too high for my car (Punto Cabriolet 1.2 16V 86ch).
When I’m riding at 90 km/h (56 MPH), the engine is at 3000 RPM, and obviously it makes me feel that fuel consumption is higher than expected.
When I drive cars with same HP like Renault Clio 3 (60 hp), it is at 2500 RPM.

Is it a common thing, or is it a problem?
Thank you for your time

 

[Pugglt Auld Jock]

looking at the mileage covered my first question would be is the clutch slipping?

 

[jim cooper]

That sounds about right for a 16V engine which delivers power at higher RPM than, say, a 3 cylinder with turbo. My Tipo 1.4 16V is running at almost 3000RPM at 56 mph in 5th gear and about 2600RPM in 6th gear. What gear are you in? My average fuel consumption over 23000 miles is 43.5 mpg.

 

[jim cooper]

Don't worry too much about your high mileage. My son's Punto 1.2 is on 185,000 miles with the original clutch and engine.

 

[cauchemarre]

Hello everyone,
Thank you for your replies. I couldn’t answer last week.

looking at the mileage covered my first question would be is the clutch slipping?

Hmm it is not, the previous owner changed it not so long ago, I think 10.000km (16.000 miles) ago.

That sounds about right for a 16V engine which delivers power at higher RPM than, say, a 3 cylinder with turbo. My Tipo 1.4 16V is running at almost 3000RPM at 56 mph in 5th gear and about 2600RPM in 6th gear. What gear are you in? My average fuel consumption over 23000 miles is 43.5 mpg.

Oh okay,
Now that you say it, it seems obvious. I only have 5 speeds, I use the C514 gearbox.
I’m not sure about my fuel consumption but I drove like 500km (800 miles) with the fuel tank full and I had to refill it so it’s like 10.6L while driving sometimes in town and other times at 90 km/h (56 MPH)…
What do you think about it?

 

[jim cooper]

I think you got the km and miles the wrong way around! 500 miles on a tankful is very good but 500 km is way too bad.

 

[cauchemarre]

Hi everyone,

I might figured something so I’m sharing it in case you have the same issue.

Today I’ve seen that the HT leads of the cylinder #1 was not properly sending the electricity to the spark plug.
Ignition is always difficult and not so long after it smells gasoline.

When I changed my exhaust I saw fuel leaking on the exhaust but now it makes sense.

Since the spark plug isn’t functioning there is no detonation in cylinder 1 which means the exhaust is escaping through the exhaust valve.

Look at how it is worn… (audio is in French)

And listen to the ignition with 3 cylinders only. It is the same with the HT lead connected since I think it is not locked like the others.

I’ve previously changed my spark plugs in April 2024 and I should’ve noticed that something was wrong…

Anyway, if you smell fuel shortly after ignition without any leak except at the exhaust it might be the case.

And even if it’s more about the gearbox, it can lower your speed at high revs because of the engine running on 3 cylinders only so be careful.

Cheers!