Get on the Stick, Save Some Gas

Manual Transmission Effective Gas Saver

Car buyers who aren’t sold on the long-term savings potential of hybrids may want to consider an older technology that has lost some favor in the United States in recent years but still delivers excellent fuel economy, performance and safety in one package.  The manual transmission is a remarkably versatile driving tool.

Automatic transmissions have undeniably improved with additional forward gears, but the high pressure required to operate the hydraulics of the system steals power and gas mileage.  Even newer CVT transmissions using belts to deliver numerous gear ratios can’t compare to the efficiency of a manual transmission being operated by a knowledgeable driver.

EPA fuel efficiency ratings are notoriously inaccurate for all types of vehicles, and their estimates between automatic and manual transmissions are particularly suspect.  The ratings between the two transmission types are typically listed as having a one or two mile-per-gallon difference in gas efficiency, but any experienced stick shift driver will not trust those numbers, because different techniques yield different results.

Simply put, the manual transmission allows far great control of the vehicle’s performance, and among the most important aspects are the rotations-per-minute (RPM) of the engine.  Lowering RPM lowers gas consumption, and a stick shift puts engine performance under the driver’s command.   

An automatic transmission maintains the vehicle’s RPM at a pretty steady 2,000 RPM or so at most speeds up to 55 miles-per-hour of speed, and the number rises from there.  When a driver of a manual transmission car obtains the same RPM, shifting gears lowers engine rotation down to about 1,500 RPM until the threshold for the next gear is reached.  That’s a significant savings of 500 RPM, but employing strategy to the process saves even more gas.

 Double-Clutching

Truck drivers have always used double-clutching as a fuel savings technique, but the same principle applies to cars.  By using the vehicles forward momentum, or inertia, the driver can shift into neutral prior to downshifting.  The RPM drops down to about 1,000 RPM while in neutral on most vehicles, and this can often be sustained for a mile or more depending upon the terrain.

A driver reaching the crest of a large suspension bridge for example can shift into neutral and coast the remainder of the way down the other side and well beyond without losing any speed.  The downshift is engaged when traffic conditions require it or when gravity slows the vehicle.  The process takes two operations of the clutch to shift, hence the term, double-clutch.

The same technique can be applied while approaching a place where the driver will make a turn onto another road or taking a highway off ramp where coming to a stop or significantly slower speeds are expected ahead.

It may not sound like a significant amount, but when done repeatedly over many miles the savings add up rapidly.  It isn’t hard to imagine a stick shift driver operating a vehicle at half the RPM of an automatic transmission for about four miles of a 20-mile drive.

Short Shifting

Short-shifting is changing gears immediately upon reaching 2,000 RPM.  In most accelerating situations, manual transmission drivers usually prefer to let the tachometer “wind out” to at least 2,300 RPM for performance reasons, but choosing to short shift saves a considerable amount of gas.

The driver actually manages the amount of gas he or she is willing to expend in any given situation instead of having it be an predetermined factor.

 Other Benefits

The critical factor is control, and a manual transmission driver also has the option of sending as little or as much torque to the wheels as a situation demands.  When merging onto a busy highway, the driver may choose to let the RPM build up for faster acceleration.  Although more wasteful of gas, the car’s performance exceeds the limits placed on a similar vehicle with a manual transmission.  The stick shift provides performance when needed and economy when it’s preferred.

Sudden braking situations can also be aided by the manual transmission by downshifting.  The RPM will go up, but the vehicle rapidly loses forward momentum because the transmission limits the speed of the wheels.  In winter conditions this is a tremendous advantage, and overall it’s a much appreciated safety feature among manual transmission fans.

 Common Misconceptions

Hills pose no threat for drivers with a manual transmission.  The clutch will hold the vehicle in place when released slowly.  Inexperienced drivers sometimes leave the clutch fully engaged for too long and experience a backward roll as a result, but it’s only a matter of practice before that’s overcome.

City driving also holds no challenges for people who prefer stick shifts.  Most of the time, the driver starts out in second gear, shifts to third, and coasts the remainder of the way in neutral between blocks.  First gear isn’t necessary to get most vehicles under 5,000 pounds moving unless there’s a very difficult incline or exceptionally slow traffic conditions.

Traffic jams can be a little more challenging because of an erratic pace of traffic, but most stick shift drivers compensate by allowing the RPM to rise until it can accurately determined whether an upwards shift is a good idea or not. 

 A Matter of Choice

When driving with a manual transmission, there’s not a tradeoff, but a choice.  It isn’t a matter of substituting performance for efficiency; it’s a preference between the two based on the situation.  The limitation isn’t engineered into the vehicle.  It’s entirely up to the driver, and most serious drivers agree that’s exactly what they want.

Save money whenever possible, get power as needed and enjoy safety when the situation demands.  The stick shift has it all.