Save gas. Drive slow.

[Sentinel]

dup

 

[Sentinel]

Had the wheels balanced twice and then aligned. Still get the vibration.

Edit: sry to threadjack.

 

[nakedfrog]

Originally posted by: BoomerD
The WOSRT gas we got came from a Shell Station outside Grand Island, Nebraska...mileage in both vehicles dropped by over 10%) (we were delivering our 1990 BMW 735i to our son in Wisconsin)

If you bought the cheapest gas they had at the pump, it was E10 89 octane, which seems to give me a 10% drop in MPG in every vehicle I've ever put it in.

 

[BoomerD]

Originally posted by: Sentinel
Had the wheels balanced twice and then aligned. Still get the vibration.

Edit: sry to threadjack.

You may have bad control arms in the suspension. That's a pretty common problem with some of the BMW 7 series cars...the bushings wear out slightly and the car develops a shimmy at about 55-60...then goes away at about 80.

Of course, it could be worn tires with bad spots or belts that have separated, or many other issues as well...

 

[DrPizza]

I may be wrong, but I think a lot of those studies are complete bullshit because they overlook one thing: other traffic.

If you're the only car on the road, then 55 may be a more efficient speed. But, if there's other traffic on the road, at 65, your car is working as hard as it was at 55 with no other traffic. Reason: air resistance. Watch bike (i.e. tour de france) racing - all those bikes clustered together are capable of traveling at a higher speed for a greater distance. Watch car racing - two cars working together, one behind the other, experience less air resistance (both of them experience less air resistance, not just the one in the back) than one car running alone would.

Now, I don't know the magic number where cars are most efficient, and I really doubt it's some magic fixed number for all makes and models. But, I haven't seen any studies that take into account the effect of more than one car on a track. i.e. highway driving with more traffic.

 

[ShotgunSteven]

Originally posted by: Eeezee

Originally posted by: ADDAvenger
Drive a motorcycle, get 3x mileage

My car (98 Towncar) gets about 20, while my 150 scooter/cycle/whatever you wanna call it gets ~65. I thought larger engines would get worse mileage, but I have a friend that has a 650 that also gets about 60mpg, but then again he didn't say if that was all-around or just highway. So what if he gets 40 around town, that's still 2x what most people have, and a bit better than most hybrids at a small fraction of the cost. Granted, cargo space is limited, and it won't work for a family, but for just yourself or a couple it's great.

Yes, dropping a few thousand pounds and significantly reducing surface area probably helps fuel economy a lot

Are you talking about the drivers or their vehicles?

 

[jagec]

Originally posted by: BoomerD
With our 2005 Expedition 4X4, driving between 55 and 60 yields about 18 mpg, where driving 70 yields about 15 mpg.
Pretty good savings IF I'm not in a hurry or going LONG distances.

The quality of gasoline makes quite a difference in mileage too. (no, not talking about the difference between "top-tier" and "normal" gasoline, but the difference in octane levels in different states and the quality of the product pumped out of the tanks.

When we were on vacation 3 years ago with the truck...(brand new, less than 1000 miles on it when we left) we encountered a LOT of difference in gas purchased in different states, (85 octane in many parts of the Rockies) and some terrible gas from various stations. The WOSRT gas we got came from a Shell Station outside Grand Island, Nebraska...mileage in both vehicles dropped by over 10%) (we were delivering our 1990 BMW 735i to our son in Wisconsin) Over the entire 6200 mile trip, we got 18.6 as a high and 14.7 as the lowest MPG's, with speeds remaining constant. (posted limits +5)

We love the Expedition, but it sure doesn't like to pass a gas station...

Is the tank really that small?

There's a Suburban at this house (used for ski patrolling, towing etc), and while it gets crap mileage it has a HUGE tank, and so the range is surprisingly good.

 

[CallMeJoe]

FWIW, Parnelli Jones.

With gas prices past $3/gal, I still see SUV/Pickup/Hummer drivers who jackrabbit every light and cruise >10 mph over the limit (75 mph +) on the highways. Either they have more money than they know how to spend, or someone else is buying gas for them. I drive a stick, accelerate smoothly, shift at low RPMs, and cruise at as steady a speed as traffic allows. I have better things to do with my cash than support Big Petrol.

 

[mcmilljb]

Originally posted by: Auryg
I also seem to remember the highway death rate dropping when Montana got rid of their highway speed limits.

Maybe because people could get away from the idiots quicker! :thumbsup:

 

[JS80]

I did a case study in college where it showed that in some instances lowering the speed limit increased the number of accidents and deaths.

 

[CallMeJoe]

Originally posted by: JS80
I did a case study in college where it showed that in some instances lowering the speed limit increased the number of accidents and deaths.

That depends, in part, on whether people observe the lower speed limit. The safest roads are those where everyone drives at a similar speed, within the conditions allowed by road design, surface, etc.

 

[JS80]

Originally posted by: CallMeJoe

Originally posted by: JS80
I did a case study in college where it showed that in some instances lowering the speed limit increased the number of accidents and deaths.

That depends, in part, on whether people observe the lower speed limit. The safest roads are those where everyone drives at a similar speed, within the conditions allowed by road design, surface, etc.

Yes, people observed the lower speed limit. That had nothing to do with the increase in number of accidents and deaths. In fact, that was the problem, people refusing the break the law.

 

[mcmilljb]

Originally posted by: Vic
edit: to the OP and the other 55-ers...

Point blank, my objection to the "save gas, drive slow" and 55 mph limits arguments to conserve fuel is that you are essentially forcing me to drive slow because you drive an inefficient vehicle. That is BS. And as I noted in the recent helmet thread, is representative of the typical American mindset where you won't do the right thing unless everyone else has to do it too.
Here's the thing, my car doesn't go into top gear until about 60 mph. I get about 26-27 mpg at 80 mph. I drop down to about 21-22 in (even frequently spirited) city driving. Your SUV doesn't get better than 20 mpg no matter how you drive. Oh, and my car has 350 hp. What's your excuse?

I'm curious to what you drive.

The automobile makers should continue to increase research into proven techniques to increase milage. If they aren't interested in doing it, the consumer just gets stuck with making the best of what's available. Better engines are sipping less fuel, and we're making cars lighter that can still be safe and have usable space.

 

[CallMeJoe]

Originally posted by: mcmilljb
The automobile makers should continue to increase research into proven techniques to increase mileage. If they aren't interested in doing it, the consumer just gets stuck with making the best of what's available. Better engines are sipping less fuel, and we're making cars lighter that can still be safe and have usable space.

There's the rub! The manufacturers, for the most part, put their efficiency improvements into more horsepower to push larger, heavier vehicles where there's more per-unit profit. What few relatively high-mileage vehicles Detroit makes are (IMHO) fugly econoboxes rather than nicely finished smaller cars. Unfortunately, until recently, most Americans were happy to buy monster SUVs and overweight sedans, driving even foreign builders to "bulk up" their products for the U.S.

 

[BoomerD]

Originally posted by: jagec
Is the tank really that small?

There's a Suburban at this house (used for ski patrolling, towing etc), and while it gets crap mileage it has a HUGE tank, and so the range is surprisingly good.

I think the tank is 28.5 gallons. Not terribly small, and with the current prices, a mofo to fill up...but not as big as I had expected it would be.

 

[Eeezee]

Originally posted by: DrPizza
I may be wrong, but I think a lot of those studies are complete bullshit because they overlook one thing: other traffic.

If you're the only car on the road, then 55 may be a more efficient speed. But, if there's other traffic on the road, at 65, your car is working as hard as it was at 55 with no other traffic. Reason: air resistance. Watch bike (i.e. tour de france) racing - all those bikes clustered together are capable of traveling at a higher speed for a greater distance. Watch car racing - two cars working together, one behind the other, experience less air resistance (both of them experience less air resistance, not just the one in the back) than one car running alone would.

Now, I don't know the magic number where cars are most efficient, and I really doubt it's some magic fixed number for all makes and models. But, I haven't seen any studies that take into account the effect of more than one car on a track. i.e. highway driving with more traffic.

At a proper stopping distance, you shouldn't experience any of the benefits of drafting (reducing air resistance by following closely behind a car). The drafting distance is much less than an acceptable stopping distance. You run the risk of rear ending someone if you try to take advantage of drafting for higher MPG.

I read a study somewhere about drafting distances, and it's only really effective if you're driving behind a semi since they take MUCH longer to stop than your car (so your stopping distance is within the range for effective drafting). Unfortunately they're also likely to drive slower than most of the other cars on the freeway.

 

[DrPizza]

Originally posted by: Eeezee

Originally posted by: DrPizza
I may be wrong, but I think a lot of those studies are complete bullshit because they overlook one thing: other traffic.

If you're the only car on the road, then 55 may be a more efficient speed. But, if there's other traffic on the road, at 65, your car is working as hard as it was at 55 with no other traffic. Reason: air resistance. Watch bike (i.e. tour de france) racing - all those bikes clustered together are capable of traveling at a higher speed for a greater distance. Watch car racing - two cars working together, one behind the other, experience less air resistance (both of them experience less air resistance, not just the one in the back) than one car running alone would.

Now, I don't know the magic number where cars are most efficient, and I really doubt it's some magic fixed number for all makes and models. But, I haven't seen any studies that take into account the effect of more than one car on a track. i.e. highway driving with more traffic.

At a proper stopping distance, you shouldn't experience any of the benefits of drafting (reducing air resistance by following closely behind a car). The drafting distance is much less than an acceptable stopping distance. You run the risk of rear ending someone if you try to take advantage of drafting for higher MPG.

I read a study somewhere about drafting distances, and it's only really effective if you're driving behind a semi since they take MUCH longer to stop than your car (so your stopping distance is within the range for effective drafting). Unfortunately they're also likely to drive slower than most of the other cars on the freeway.

I fully agree about the stopping distance. However, on many freeways/highways, cars are not at a safe stopping distance (hence the multi-car pile-ups.) IIRC from my youth, you're supposed to be 2 seconds behind the car in front of you. That simply doesn't happen - it means there are only 30 cars passing a point per minute, or that a road can only handle 1800 cars per hour per lane. That seems a lot lower than what I'd estimate is reality for busy roadways.