Best RPM?

[Anbele]

So I’ve come across lately on other car forums discussions and videos that European cars tent to “behave” better at high RPMs, while American counterparts like lower RPMs…Thus—to prove this theory—lately I’ve been driving my ‘79 at higher Rpms. Like now I rev 3rd to 4500/4800 before going into 4th; and similarly, rev 4th to 5500 before going into 5th…So, is this okay to do? Or am I stressing the engine/transmission too much? (And btw, this is not done on a track…just don’t tell your friendly hwy patrol)

[Nut124]

Totally OK if the engine is in OK condition. The 2L makes peak power at around 5500 in stock condition.

Trans is fine too as long as you do not rush, force upshifts, 2nd to 3rd and break the synchros. The rear diff is weak and can break if doing hard launches w sticky tires.

When in a hurry, I shift my 1800 at 7500rpm but it has been modified. Makes peak power at 7300-7500.

[18Fiatsandcounting]

So I’ve come across lately on other car forums discussions and videos that European cars tent to “behave” better at high RPMs, while American counterparts like lower RPMs…

It's not that the engines like certain rpms ranges, it just depends on where their torque peak is. Large American engines have traditionally developed their peak torque at much lower rpms than smaller European engines with their shorter strokes. So, you have to wind out the smaller European engines to accelerate, pass another car, climb a hill, etc.

Where to shift is totally dependent on how much power you need and how much gas you want to use. Could be 2500 rpm on a flat road with slow acceleration, or 6000 while passing another car on a steep hill. Winding out an engine uses a lot more gas, so there is that to consider.

And, if you're a nut like Nut124, you shift at 7500!

-Bryan

[TX82FIAT]

I think you are on point for the most part with your driving revs. I tend to drive all day in the 3000 to 3500 RPM range ruining it up to 4000 - 5000 RPM's based on the gear as you mentioned on a typical shift. I'm a terrible passenger when my wife or kids drive the car because they want to shift like a modern manual at 2000-3000 RPM's. The only caution in this area would be if you have a modified over stock engine. Once you go from 8:8:1 to 10:1 or 10:2 compression and start pushing the engine pretty hard the likelihood of blowing a head gasket goes up a little. Ask me how I know. They have a higher compression "thicker gasket" that in some ways defeats the purpose of a HC volume adjustment by lowering the compression ratio. For this reason only, I tend to keep the 40 year old car with a 9 year old head gasket under 6500 RPM's. She has plenty of power above 4000.