Ford Escape Automobiles Forum banner
1 - 20 of 21 Posts

·
Registered
Joined
·
9 Posts
Discussion Starter · #1 ·
I own a 2005 ford escape v6 awd and im geting about 300kms per tank of gas (60L), i am only do city driving however im driving very 'softly' and rarely have the engine about 2300rpm. is this normal fuel economy?
 

·
Registered
Joined
·
178 Posts
That doesn't tell us much. How much time do you spend at idle?
 

·
Registered
Joined
·
178 Posts
When I got my Escape with its MPG computer, I learned that I idled much more than I thought I did. Fuel economy goes way down when you visit the bank, drive-thru, stop lights, etc. I also learned that acceleration wasn't as much of a factor. Certainly you shouldn't floor it every time you pull away from a stop, but accelerating so slowly that even grandma runs you over, doesn't improve MPG that much.

On the highway I can improve my mpg by 4 miles per gallon just by slowing down from 70 to 60 mph.

Empty everything out of your car that you don't absolutely need. Weight is a big factor. If you don't need a full tank of gas, then filling up half way can save weight. Pump up the tires to Max PSI to decrease rolling resistance and don't use aftermarket wheels. Coast to intersections from as far away as possible. Make sure your air filter isn't dirty. Wash and wax your car.

In many cities you can "time the lights." Often if you travel 5 mph less than the speed limit in urban areas, you can catch most of the lights going one way.

There are lots more techniques. Google "hyper miler" and you should find plenty of resources.
 

·
Premium Member
Joined
·
4,977 Posts
Hypermiling has been ruined by a few stupid extremists. Their methods cause more damage to traffic flow than can be justified for their own tiny MPG gain; coasting to ridiculous levels, or keeping "constant pressure" on the gas while going uphill, slowing everyone down and backing up traffic. Even using max PSI on your tires is dangerous - I would limit yourself to 3 PSI above factory specification, and check it once a month. Check once a week when temperatures are fluctuating before and after winter. Make sure you check on a cold tire that has not been driven on or exposed to sunlight for the past four hours. Don't use defroster modes in the summer as that turns on the A/C compressor.

Avoid warming up in the winter as fuel injected engines do not need it, but keep the defroster on mid-blast until the engine warms up, in case condensation builds up on the windshield.
 

·
Registered
Joined
·
1,081 Posts
I've been averaging far more kms per tank on my 06' V6. Usually 550-600 kms per tank with mixed driving. The only time I notice economy really suffer is when I do short hops, a lot of starts and stops without the veh really warming up. This city has a lot of streets that travel at 60-70 km/h so that may be helping a bit but 300kms to a tank seems very low.
 

·
Registered
Joined
·
178 Posts
Even using max PSI on your tires is dangerous - I would limit yourself to 3 PSI above factory specification, and check it once a month.
Factory PSI is very low. I think Ford says 32 PSI for my tires. The dealership had them set at 35 PSI.

You shouldn't pump them up to the maximum sidewall pressure that is inscribed in the tire. My Michelins specify 44 PSI. You could go as high as 40 PSI safely. I rarely go above 35 PSI because it's like riding the Flintstones car that used rocks for tires.
 

·
Registered
Joined
·
178 Posts
Got any data to support 40 PSI as safe?
It is inscribed right there on the sidewall of the tire.
 

·
Premium Member
Joined
·
4,977 Posts
No it isn't. 40 PSI will alter the contact patch and affect handling and stopping distances. I have a study somewhere showing that each vehicle has a tire pressure "sweet spot," and the range isn't that much. I'll post back when I can dig up that study.
 

·
Registered
Joined
·
178 Posts
No it isn't.
Yes it is. Here is a picture.

And a snippet from the tirerack.com website, says,

"A tire's "maximum inflation pressure" may be different that the assigned tire pressure used to rate the tire's "maximum load". For example, while a P-metric sized standard load tire's maximum load is rated at 35 psi, many P-metric sized standard load performance and touring tires (my Escape is equipped with Michelin Latitude Tour) are designed to contain up to 44 psi (and are branded on their sidewalls accordingly). This additional range of inflation pressure (in this case, between 36 and 44 psi) has been provided to accommodate any unique handling, high speed and/or rolling resistance requirements determined by the tire and vehicle manufacturers"

Under inflation is dangerous. Tires that are under inflated will wear faster than tires that are fully inflated. Tires inflated to maximum PSI will have equal contact patch and will perform on most road surfaces as well as when inflated to maximum load pressure.
 

·
Registered
Joined
·
69 Posts
I agree with KC5.

I have been running my tires at max pressure as indicated by the sidewall for about 25 years and the only blowout I have ever experienced was from under-inflation (slow leak on a long drive). I don't see how running max pressure in daily driving is bad. For my money it is much safer and better for your tires than running under-inflated.

If your tires wear in the middle at max pressure then your rims are too narrow. I'd like to see your data that says running 40 psi is *not* safe.
 

·
Registered
Joined
·
490 Posts
Talk to any tire dealer, or auto dealer, and I highly doubt they will ever recommend running tires at max pressure all the time. I'm with Squishy on this one. The vehicle manufacturers have tire pressure ratings for a reason. Sure, you may fluctuate +/- 2-3 PSI, but I would never run 40-45 if my sticker states 30. Max means just that, "Max" -- not where you should run them constantly. If you put 44 PSI cold pressure, what do you think it is after driving 70 MPH down the highway for several minutes. You're now over max.

Nobody said anything about running "under-inflated". Using the door sticker pressure vs. "max" pressure is not "under-inflated".
 

·
Premium Member
Joined
·
4,977 Posts
Not sure about tire or auto dealers, but talk to Michelin, Firestone, Goodyear, etc. Ask them "My vehicle placard recommends 30 PSI, can I run 40 PSI since max pressure is 44 PSI?" Just because the tire won't blow does not mean it is safe. We still have tire dealers here that hire people who recommend two winter tires on the front wheels, so I don't trust them much.

I think I deleted that study as I finished reading it several years ago, but it was done by the NHTSA and measured effects of tire pressure on stopping distances in 5 PSI increments, using three vehicles (sedan, minivan, and light truck) on stock tires. The sweet spot usually fell either one increment (5 PSI) above the vehicle placard, or exactly at the recommended pressure. Above and below that, stopping distances increased by several feet per increment. However, the vehicle placard is only valid for the load rating of the OE tires. Higher load ratings require lower tire pressures, while lower load ratings require higher tire pressures. I have a rough formula here, but it may not hold for large changes, such as going to a 20" wheel. The best way would be to get your hands on a load-inflation table published by the RMA.

Tires will wear faster on the sides/shoulders when underinflated, but will wear equally fast down the centre when overinflated. Contact patch certainly does change - the shape of it may not change much, but you want relatively equal pressure distributed across the contact patch. That will not happen at 10 PSI above recommended - you will have high pressures at the centre and lower pressures on the sides.

Since we're quoting TireRack,
While a wide variety of tire sizes are available to fit the many different vehicles in use today, almost every tire size can be used on more than one vehicle. Therefore it is the vehicle manufacturers that ultimately determine the tire inflation pressures they believe best fine-tune the tires' capabilities to their specific vehicle makes and models.

The pounds per square inch (psi) pressure number branded on the tire's sidewall identifies the maximum cold inflation pressure that specific tire is rated to hold. However, the tire's maximum pressure is not necessarily the correct pressure for every vehicle upon which the tire can be used (almost all vehicle manufacturers' recommended tire inflation pressures are less than the tires' maximum pressure).

Therefore when checking and adjusting tire inflation pressures, the "right" inflation pressures are those provided by the vehicle manufacturer, not the "maximum" inflation pressure branded on the tire's sidewall. The vehicle manufacturer's pressure recommendation can be found on the vehicle's tire information placard label, as well as in the vehicle owner's manual.
An overinflated tire is stiff and unyielding and the size of its footprint in contact with the road is reduced. If a vehicle's tires are overinflated by 6 psi, they could be damaged more easily when encountering potholes or debris in the road, as well as experience irregular tread wear. Higher inflated tires cannot isolate road irregularities as well causing the vehicle to ride harsher and transmit more noise into its interior. However, higher inflation pressures reduce rolling resistance slightly and typically provide a slight improvement in steering response and cornering stability. This is why participants who use street tires in autocrosses, track events and road races run higher than normal inflation pressures.
And a nitpick: "Maximum load pressure" is maximum inflation pressure. Load rating may be measured at 35 or 41 PSI, but the load capacity does not taper off after that point. Higher pressures = higher load capacity.
 

·
Registered
Joined
·
178 Posts
The max pressure on the sidewall is the cold pressure. As the tire heats the pressure will increase as much as 5 or 6 psi. This does not exceed the rating of the tire, which is actually closer to 51 psi.

Tires will burst at 300-400 psi, so I wouldn't worry about a blowout from fully inflated tires. Most blowouts happen with under inflated tires.

Fully inflated tires will not wear out faster in the center. That would happen if the tires were OVER inflated. 40 psi is not over inflated. In fact the contact patch in wet conditions will be much better than if it was under inflated.

No dealership, tire store, or even tire manufacturer, will ever tell you to inflate your tires above the pressure indicated on the placard located on the drivers door. Ever. Why? Liability. Is there a safety factor driving down the road with fully inflated tires? NO. Then why the liability issue? If the tire isn't properly seated, then it could blow off the rim while you are adding air, possibly causing injury or death. That's it.
 

·
Premium Member
Joined
·
4,977 Posts
40 PSI is OVER-inflated by 10 PSI. Slight over-inflation does help on wet asphalt, but not on wet concrete. It won't help in the dry.
 

·
Registered
Joined
·
142 Posts
Squishy is correct. The max pressure on the sidewall is the max pressure you could put in the tire to carry a load up to the load rating. The manufacturer specified pressure is the optimum pressure to carry the weight of the vehicle while optimizing ride, handling, stopping, and fuel efficiency. If you are inflating OE tires over the manufacturer specification, then you are over-inflating and affecting the contact patch, and, therefore, affecting ride, handling, stopping, and fuel efficiency. You may get better gas mileage, but you adversely affect something else, like stopping distance and/or ride quality.

On my first car, a 1989 Ford Probe GT, the specifications were different for front (higher) and rear (lower) even though the tires/wheels were identical. Had I inflated all four tires to the front specs PSI, the two rear tires would have been over-inflated under the circumstances even though well under the max pressure indication on the sidewall. Same thing here.
 

·
Registered
Joined
·
9 Posts
Discussion Starter · #19 ·
ok cool. unfortunatly ive run out of time for the rest of the week to be paying too much attention to this as ive got so much going on this week. ill try to reply later on this week or this weekend and let you know how things are going. I am currently doing a little test as yesterday i filled my tank up and this next week im doing more of a mixture of driving, some on city streets and like 5-10 mins on the hwy so im going to go 100kms and go fill my tank up when i reach that to see how many liters ive used. Maby ive got such bad fuel economy the last week or 2 as ive been doing only 5km trips each way so the engine hasnt probably come to temperature.

Thanks again
 

·
Premium Member
Joined
·
4,977 Posts
The hypermiling techniques are still a good read, but keep in mind the golden rules: Don't upset the flow of traffic, and don't do anything unpredictable to other drivers.

One thing I do that doesn't appear in many hypermiling discussions is "rev-matching" for automatics. When you know the transmission is about to shift, lift your foot from the gas pedal to drop the engine speed. This is much easier than in a manual, as when the engine reaches a low enough speed, you should feel a firm shift to the next gear (instead of the flare you sometimes get at higher loads). The Escape's transmission shifts firmly and smoothly at 20 and 40 km/h, but I use this technique at 55 km/h and 70 km/h to lock up the torque converter. Otherwise, it will shift instead at around 60 and 80 km/h. This is only useful on flat roads, as you want the engine speed higher up at around 2500-3500 RPM when going up a hill.

How about a bike for 5 km trips? :D
 
1 - 20 of 21 Posts
Top