What should your engine RPM be at highway cruising speeds?

One thing which interests me of any new car is the engine speeds /RPM at different cruising speeds. That,sort of,gives a rough idea about the category/segment of the cars it’s competing with,NVH levels & comfort (rough idea as it depends on build primarily ), Fuel efficiency.

When do the RPMs go up or down?

For example, RPM’s quickly move from 1,250 to 1,500 at 45 MPH. This problem has been ongoing for two years (and driving me a bit mad). The condition is most pronounced when traveling between 15 and 45 MPH. I’ve never once noticed the condition at highway speeds (above 55 MPH.

What are the RPMs of a car at 45 mph?

RPM’s rapidly fluctuate up and down even when on a flat road under constant throttle, speed and load. For example, RPM’s quickly move from 1,250 to 1,500 at 45 MPH. This problem has been ongoing for two years (and driving me a bit mad). The condition is most pronounced when traveling between 15 and 45 MPH.

What causes the tachometer needle to bounce while driving?

The bounce of the tachometer needle happens when speed is constant under little to no torque, anywhere between 30-58 km/h, the RPM ranges 1300-1800-ish {if I press or release the accelerator slightly the RPMs stay steady, and the bouncing tach needle stays steady}.

What makes a good cruising rpm for a car?

Basically its all in the combination and the compromise – just like with anything else motor related. Best cruising RPM relies heavily on cam timing, port efficiency, exhaust scavenging, pumping losses, BSFC/SFC, engine torque characteristics, aerodynamics…the list goes on and on and on.

What should the cruising rpm be on a 283?

You should be looking for 2200-2400 cruising RPM at around 70-75 MPH, at least a 3:73 gear, but check out the article, Hotrodhill. The 283 is gonna like the extra gearing with the taller tires….especially since your using the 462 heads…..small cam or not.

How does the efficiency of an engine vary with speed?

Engine efficiency varies with speed and torque. For driving at a steady speed one cannot choose any operating point for the engine—rather there is a specific amount of power needed to maintain the chosen speed. A manual transmission lets the driver choose between several points along the powerband.

Which is more energy efficient coasting or friction braking?

Using stored energy (via coasting) for these purposes is more efficient than dissipating it in friction braking. When coasting with the engine running and manual transmission in neutral, or clutch depressed, there will still be some fuel consumption due to the engine needing to maintain idle engine speed.

What’s the best speed for an energy efficient car?

Maintaining an efficient speed. The optimal speed varies with the type of vehicle, although it is usually reported to be between 35 mph (56 km/h) and 50 mph (80 km/h). For instance, a 2004 Chevrolet Impala had an optimum at 42 mph (70 km/h), and was within 15% of that from 29 to 57 mph (45 to 95 km/h).

What does intermittent engine cut-out mean for car?

Most days when the car reaches normal working temperature, the engine shuts down intermittently. This may be only one or more brief jolts or it may stay off for several seconds. This happen while driving 70+ mph on the highway. Ones it passes this phase it continues to run normally for the remainder of my 50 mile commute.

What kind of car loses power at highway speed?

2003Nissan Altima 2.5s…. while driving at highway speed {60} the car lost all power and died and all dash lights went off. A second or two later all the lights on the dash and headlights as well as radio came back on. I tried to put it in neutral and restart it while it was coasting but the starter wont engage to try and start motor.

What causes an engine to misfire at freeway speeds?

The engine may misfire and/or buck while driving at freeway speeds with no fault code stored in the powertrain control module (PCM). This can be caused by an intermittent fault with the camshaft synchronizer assembly.

Why does my engine cut out after a second?

Some of the solder joints were cracked and caused the intermittent trouble. It would actually start, run for just a second and cut off. It was similar to the fire in start, but not in run described above. I simply cleaned the coating off the panel back and resoldered any connection that looked like it may be cracked.

Why is my car surging at idle speed?

When an engine’s computer can “hunt” or “surge” at cruising or idle speeds it is searching for program compliance, there is a problem elsewhere in the system.

What causes an engine to surge during a tune up?

Step 2 – An engine’s tune up is a regularly scheduled service, when this service is neglected it can cause the engine to surge. Learn more Step 3 – If a fuel pump or regulator is failing is can cause an unsteady volume or pressure for the fuel system causing the engine to surge. Learn more

What happens when engine surging causes engine to lose speed?

Engine surging, will cause the engine to momentarily lose (rpms); but then regains, normal engine speed. Engine surging, can affect drivability but; can also cause error codes to appear in your, OBD-II system.

What causes an engine to surge at idle?

A surge is usually caused by a fuel system management or drivetrain operation failure. When an engine’s computer can “hunt” or “surge” at cruising or idle speeds it is searching for program compliance, there is a problem elsewhere in the system. SPONSORED LINKS. Article published 2017-01-26.

What causes Chevy 5.3 liter engine to surge?

Discussion in ‘ Community Campfire ‘ started by HighDesertWolf, Apr 30, 2009 . My 1999 silverado with the 5.3 engine. the motor will occasionally surge at crusing speeds between 40 and 60 mph. I figured out how to induce it by letting off the gas and quickly giving it 1/4 throttle and about half the time this will cause the engine to surge.

When to set DTC for engine surge maintenance?

• After driving at 6.25 mph or more, the actual engine idling speed varies from the target idling speed by between 100 and 200 rpm, five times or more during a drive cycle. • If the actual idling speed varies from the target idling speed by more than 200 rpm five times or more during a drive cycle, the ECM illuminates the MIL and sets the DTC.

Can a vacuum line cause an engine to surge?

Learn more Step 5 – If a vacuum line has caused a leak the engine will surge, as vacuum lines age they can become brittle and fall off the engine or accessory. Learn more Step 6 – If an air intake boot becomes torn and develops a leak it will cause the engine to surge.