Date post: | 11-Sep-2014 |
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Automotive |
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How Fuel Trumps Mileage – Every Time
FUEL FACTORS FOR FLEETS
What Is Fuel To You?
• Your Largest Cost after Salaries
• Equal to Salaries at $3.29/gallon
• Lost Expense in Surcharges: Large Fleets not recovering full costs
What Does Fuel Really Cost?
• Fifty Truck Fleet achieving 6.0 MPG• Prices of diesel - $3.00/gallon• Assumes 130,000 miles per year
• Your fleet spends $61,280 per truck• $3,064,000 in fuel per year
• Decrease fuel economy to 5.6 MPG = You now pay $65,640 per truck and $3,282,000 per year– That’s an additional:
• $4,360 for each truck• $218,000 for your fleet
Diesel prices leveling –
but when will it rise again?
HOW FLEETS CHANGE FUEL ECONOMY?
OK, fuel is important but…
SAE Factors Affecting Fuel Economy• Controllable:
– Speed– Inflation– Air Resistance– Tire Rolling Resistance– Load– Drive Line Friction
• Not Controllable:– Road Surface– Ambient Temperature– Terrain
The Cost Of Speed-Controllable Factor
6 MPG
5.5 MPG8% Loss
4.4 MPG26% Loss
3.6 MPG40% Loss
Source: Paccar/Kenworth
65
60
70
75
Inflation - Controllable Factor
• 90% of tire failures stem from improper inflation
• “Tire tread wears 9 -16 percent faster for every 10 percent a tire is below its fleet specified pressure.” - TMC
You spend 1% more on fuel
With every 10 PSI of underinflation!
Inflation in the Real WorldContinental study
0
20
40
60
80
zu hoch >10%
i.O. zu niedrig >10%
too high ok too low0
20
40
60
80
zu hoch >10%
i.O. zu niedrig >10%
too high ok too low
30% of power units are running too low!
40% of trailers are running too low!
Inflation pressure 100%
Correct value
Inflation pressure 130%
Overinflation vs. load
Inflation pressure 70%
Underinflation / overload
Increased deformation: = increased fuel consumption= increased stress
Inflation Effects
DRIVING RESISTANCE FACTORS
Controllable Factors: Once the easiest factors (speed and inflation) are controlled, we have to account for driving resistance factors.
Driving resistance - Impact on fuel consumption
Driving power = Driving resistance (aerodynamic, acceleration, uphill and rolling) x speed
Driving resistance - Impact on fuel consumption
35%
At average fleet operating conditions – between rural and highway operations – rolling resistance accounts for about 35% of fuel consumption.
Aerodynamics – Controllable Factor•20
% better fuel economy
•Aerodynamic truck vs. no aerodynamic devices
•5-10%
•Adding full roof flairing when pulling a van trailer
•2-4%
•Adding options such as side extender flairing and chassis flairing
•1-2%
•Using under hood air cleaners vs. cowl mounted air cleaners
•1-2.5%
•Using proper fifth wheel settings at an optimal 38” trailer gap
TIRE ROLLING RESISTANCEControllable Factors
Rolling Resistance Effect on Fuel
Steer Axle: 15% of RR
Drive Axle: 42.5% of RR
Trailer Axle: 42.5% of RR
FUEL FACTORS THE FLEET CAN CHANGE
Recommendations: CommonSense Maintenance• Inflation
– Twice Monthly Airing /Inflate Trailers/Flat Checks– FMCSA Roadside Survey: only 44% of all tires are within 5PSI of their target
inflation– 12% of tires of surveyed tires are in danger of premature failure– Properly Inflated Tires:
• Wear more evenly and at a slower rate• Ten PSI below recommended pressure costs 1% in fuel economy• Fleet inflation programs reduce road calls
• Fuel Efficient Tires and Retreads• Alignments/VAI• Matching of Tires• Management Commitment
Recommendations: Common Sense Driving
• Review Speeds: 70mph to 67mph saves 5%– Use the cruise control– Optimal RPM for the Engine
• Reduce Idling• Fleet Top Fuel Performers Driver training• Driver Training TMC• Driver Incentives (Speed Bonuses, MPG
Average)• Progressive shifting/ Staying in High Gear
Avoid These Fuel Wasters
• Excessive Speed• Stop-and Go Driving Style• Under Inflated Tires (10% Under =1% Loss)• Long Idling periods over 5 minutes• Misalignment• Open Windows (Loss is 4%)• Running A/C• Mismatched Tires • Fuel Inefficient Tires• Idling
Future Focus on Fuel ConsumptionSmartWay Partnership
Steer Drive Trailer
HSL2 HDL Eco Plus** HTL Eco Plus**
HSL2 Eco Plus HDL2 Eco Plus HTL1
HSR* HDL2 DL Eco Plus General ST250
HSR1*, Eco Plus* HDR
HSR2*, Eco Plus* HDR1
HSR2 SA* HDR1 Eco Plus
HSL1 Coach* Conti EcoPlus HD3
General S371* Conti Hybrid HD3
General S580* General D660
General S581*
The SmartWay Web site is the final authority for tire approvals.
*Also Drive verified**ContiTread retread also verified
Continental and General SmartWay Verified Tire Products as of June 2013
Fuel Over Mileage: YourMinimum Savings Fuel Cost
$ 3.00/gal