Can't Get Away From Old Car People & Gas Mileage

[Norm's Coupe]

.........

Edited September 23, 2009 by Norm's Coupe

[Don Coatney]

The dealer is correct. Things I have learned. I drive around 70 miles daily round trip to work in Smashville. If I drive my truck (furd F-150) 70 MPH I burn a tank of gas (20 gallons or 75 bucks whichever comes first) in 4 days. If I drive 55 MPH I get 5 days from the same tank of gas. That is a 20% increase in fuel mileage. I now drive 55.

Also everytime you step on the brake you waste the gasoline it took to get you up to speed to begin with. If I can coast to a stop I will do so.

[Merle Coggins]

Wasn't that the purpose for the Federal mandated 55 MPH speed limit back in the 70's?

[Young Ed]

I swear its vehicle dependant. My 94 dakota was bought new by my dad. When he got it the speed limit on 35W was 55. We used to go 60miles to the resto shop and a little later further trips to the cabin. He would typically go 60 in the 55. Always got 19.x MPG. Now I can do that same drive to the cabin at 70-75 and get the same MPG. And now that my catalytic convertor lost some of its guts I get 22-23mpg. Go figure.

[BobT-47P15]

I don't check gas mileage very regularly, but on occasion it seems my 06

short Caravan will get from 19 to 23 mpg on highway driving at 65 to 75 mph.

I will try to check it again tomorrow as we drive to Nashville.

Will try to get togther with the correspondent above, Mr Coatney, and also

with Chance Moore (wayfarer stranger) while in the Music City.

[PatS....]

My 88 Ram 318 was horrible on gas a couple of years ago and after replacing the O2 Sensor, mileage almost doubled.

Now, it's horrible again and the code shows the Automatic Idle Speed Motor is gone.

Lots of these newfangled things can affect the mileage significantly.

I now know what the 02 sensor looks like and where it is but the AIS could be behind the taillight for all I know...buncha crap:mad:

[blueskies]

Since winning a Civic Hybrid, I've been reading up on the car and it's mpg capability. I've learned a new term in the process, "hypermiling". Seems that with carefull driving, one can attain mileage well in excess of the EPA ratings for this car (45hywy), into the 65 to 80 mpg range.

So, being eager to try this out, but not having the car yet, I decided to try the basic techniques of hypermiling on my '07 Totota FJ Cruiser.

My regular commute back and forth to work is about 15-20 miles each way, and I usually get about 15-16 mpg.

I have a ScanGaugeII guage on my FJ, and it is a digital guage that plugs in to the scan port under the dash. This gauge gives a whole bunch of data from the car's computer, including daily mileage, tank mileage totals, miles to empty, engine temps, etc, etc.

So for the last week or so, I've been trying to drive the rig to get the optimal mpg. The guage has a readout for current mpg, that changes as your foot moves the throttle. I've found that by watching the guage, and very carefully applying throttle, I can improve the mpg by quite a lot. The last two tanks I have averaged 21 mpg on the same commute, 5-6 mpg more than driving without thinking about what I'm doing. At $4.20 per gallon, that adds up fast.

My FJ is a six speed manual, AWD. I have found that it gets better mpg in taller gears, at the same acceleration. Each succesive gear gets a few mpg better, so by shifting sooner, I'm leveraging my average mpg up. I'm shifting before 1500 rpms and am in 4th or 5th, when before I'd be in 2nd or third, and still not lugging the engine. When going down hill, if I put in the clutch, or coast in neutral, the mpg shoots way up becasue there is no engine braking consuming fuel.

Also, it's amazing how sublte the pressure on the throttle pedal is in order to change the mpg on the gauge from 12 or 13 mpg, to 20-25 mpg. The difference in accleration is almost unnoticable, but just a hair more throttle, and the mpg drops a whole bunch.

All of this is sort of obvious, but with the gauge, you can fine tune your driving, and find where your car can optimize the mileage.

Pete

[TodFitch]

1. Force required to overcome rolling friction is linear with respect to speed.

2. Force required to overcome air resistance increases as the square of the speed.

3. Power required to maintain a steady speed is force times speed.

At higher speeds the wind resistance is the dominate factor, so basically your power requirements increase as the cube of your speed. It takes just over twice as much power to move your car at 70 MPH as it does at 55 MPH.

Since you typical internal combustion engine is most efficient at about 80% of maximum BHP RPM and cars are geared for higher speeds, it does not usually take twice the fuel to run at 70 as 55 but will require more fuel per mile.

I don't drive the 1933 at 70. Or even 65. So I can't comment on its gas mileage at those speeds in that car. However my 2004 Prius gets between 45 and 50 MPG at 70 while it gets around 60 MPG when the speed is 50 to 55.

[rockerbillykat]

Isnt it horrible these days,that we are all so mindfull of our fuel consumption on a day to day basis!

Even my good old self,has to go easy on the pedal now!

Fuel in Melbourne Australia is now at (AU)$1.47 PER LITRE! and will rise too

(AU)$1.60 PER LITRE by next week!

So by the time im finished building my D25,I might be able to invite friends over to have a look at it and talk about the old times when we could all gas up for a few bucks and drive all day.

We have been told by our new Government and its representitives that by Christmas we will be paying (AU)$2.00 PER LITRE!

Thats about $8.00(US)+ A GALLON!

[NatesSedan]

A couple weeks ago I started to think my trucks MPG had decreased. So I did a couple tests with driving. Instead of taking off fast and putting my foot into the pedal I would take off slow and ease up to speed. I too didn't hit the brake as much. My first tank (without the changes in my driving habits) was 16-18 MPG and the second tank after the changes I ended up with almost 100 more miles on the one tank. 25% savings by changing my heavy foot.

Some of the hyper miling techniques are a little scary. I have seen that people are putting their car in neutral and shutting off the engines when going down hill to save gas.

[james curl]

I have had a vacuum gage on my 55 Chev 235 I/6 pick up for years and the slightest pressure on the throttle pedal will reduce the vacuum from 10/12 inches at 60 to 0 inches with no noticable gain in speed. Depending in the manifold pressure that your power valve opens you might drive for miles with the power valve wide open. If I try to drive 70 in OD in my pick up the manifold pressure will drop to less than 5 inches of vacuum which opens the power valve on the 390 cfm 4 barrel at 8 inches of vacuum. This is a case of too much gear for the engine requiring almost full throttle to maintain 70 mph on level ground in OD.

[greg g]

I drive new cars for a local dealership on dealer trades. Thursday I to a hunders or so miles each way. On the way down I took a Dodge caliber. You know those things that look like somebody backed a dakota into a Pontiac Aztec. these things have a engine that is made by a chrysler hundai mitsubishi co effort that are noisey gutless and when conected to the CVT transmission drive like a snowmobile. Any way I believe they have a 13 gallon tank. I grabbed the car, and it had just a bit less than half a tank. As I pulled in the other dealers lot the low fuel light came on. So lets assume there was 5 gallons in the tank when I started and maybe 2 left when the light came on. so it used around 3 gallons to go 110 so lets call it 33 mpg, this an a mix of interstate, and two lane. I set the cruise for about 72 on the highway and 62 on the state roads. Went through a couple villages and a couple stop and go construction areas. The car had 8 miles on it when I started the trip. Coming home was in a Hemi half ton 4wd pickup. I believe these have that variable displacement crap on them as it was doing some strange stuff on the highway. So the return trip I took a different route to avoid the construction sites, and added 2 miles to the return trip. I put 50 dollars of regular in to start the trip just over half a tank. The computer said i was getting 11.2 mph. I did a reset after I got the gas and it jumped to 12.4, when I pulled into the lot here, the puter was at 14.6. I should mention that driving these dodge pickups I have never seen more than 16 mpg. Driving vans, still the bread and butter of this dealership, I have never seen more than 22 this being on the thruway from Niagara Falls to Syracuse (tail wind) Most of the vans I have driven show 18 to 20 on the compuer which I believe are optomistic in their computations. The newer vans are heavier, bigger, more square and have a 4 liter engine, so I would expect they would get poorer mpg than last year's with a smaller engine less weight and better aero.

On the home front. I put 6.3 gallons of gas in my Jetta wagon and over two week of local errands and trips, got 205 miles on the trip odo. In my Cherokee, I an now trying to keep it below 2500 rpm, and it is giving me right around 19/20 in very irregular usage.

The hyper milling stuff is kind of intersting but alot of it seems to be based on very OCD type behavior from a bunch of Anal folks.

Back in the first fuel crisis, I had a Nissan King Cab Pickup. It had 2 liter with a 5 speed. It would get about 24 mpg in normal driving and about 26 on a trip. I made some covers to smooth out the head light area, built an air dam below the front bumper, covered all of the grille, as there was an opening below the bumper, took off the west coast mirrors, and made a cover for the bed. picked up about 2 mph in normal driving, and got nearly 30 on the highway. I am fixing to make a grille blocker for my Jetta, and somebody removed and discarded the under engine plastic tray which I am building a replacement for. I have gotte 37 on the highway with that, I will be tring for 40. I will probably still use my 72 cruise control setting for highway purposes.

driving 55 or even 65 around here is dangerous.

[bob_amos]

I think that we all know that with speed comes cost so driving at a slower pace will give us more of that desired MPG. But as to the comment of the dealer. Having worked for dealers for over 40 years the one thing that I defenately learned was that most employees at these places don't have a clue what they are talking about. Even in the service department. As a matter of fact when I left dealers 15 years ago to open my own shop a dealer was what the corner filling station was for many of us in the 70's and earlier. Remember when you went to a filling station and pumped gas? Later you got to actually work on cars. Well, dealerships are the place where new mechanics start out. That is the real reason for my leaving them. At my last dealer out of 12 mechanics we had only 2 had anything more than 2 years experience. And sales??? These guys didn't even know what body types they were selling They just knew the name and that a commission was attatched to them so certain vehicle were pushed to max out their commission and some didn't even know what a MPG meant. Really!!! And management were suppose to be business guys not car guys. So when a dealer says something I never believe them. Even today my company has the rely on them for parts and information at times. I always take that advise with some question as to accuracy.

[greg g]

As I was walking through our service area the other day, I over heard a conversation between the dealership's general manager and a woman customer who was upset about a brake problem she was having. I noticed her mini van and the front wheels were black with brake pad residue. The sides of the car were covered with pad/rotor residue and the rust associated with leaving it on there. So the customer was saying she was upset because she was having to have her brakes replaced again after only about 6 onths of driving. My quick diagnnosis was either she had stuck calipers or she drove with her foot on the brake pedal all the time. Any way the GM asked her if she drove her van in the rain. She said yes, so he told her that since it rains so much in Syracuse, that it causes accelerated wear of the brake rotors. He basically told her not to drive in the rain unless she absolutely had to. I had to bite my tongue to keep from laughing, I caught the eye of the service manager (who is inspite of his job a decent and knowledgeable guy) and he was standing there with his chin on his chest in disbelief. The service manager had a further conversation with her and made an appointment for the following day which he agreed to charge her for labor only in repairing her brakes. She pulled he car out of the service bays, and left the dealership. Brake light lit all the wa out of the garage, throughthe parking lot down the service drive, and down the road. I looked at Ed the SM and said hope i doesn't rain.........

[bob_amos]

Greg's post supports what I am saying. There are a few guys in a dealer that know what is going on and it is unfortunate that they are not the guys to explain the troubles on a vehicle at first. And...when they are asked they try to be truthful knowing full well that their explaination might step on the toes of anyome who previously explained a problem incorrectly. Hoping that the customer doesn't say, "Well so and so told me this..."

Norm, To answer your question on the computer thing. You would be surprised how many people come into my shop and say to install this or that. If we just did that the vehicle may not be repaired. Then they point finger at the service people as the reason and want us to fix it with no additional charges. What we do is advise the customer that we can do as they ask. If it fixes it, and it might, great. But if it does not then the cost of diagnosis is theirs. They always ask, will that money from the original non fix be credited to the actual repairs? Like we do the work asked for then if it does not work they want their money back so they can do it right. We tell them no, it is a service and there is a price for that service and the repair is another service and there is a price for that too. The next thing is, if they say go ahead and confirm that what they wanted was right, they almost always say that why should they pay for checking it out when they already knew what was needed. I have to tell them that the gamble is theirs. Do they want the part replaced and see or do they want us to find out what really is needed even if their diagnosis is correct? Now, we use computers to look at the data stream and troube codes. We also use computers to activate various systems within the vehicle to see if the computer can command and if the item commanded will respond. You would be surprised at the number of times the actual fix is not even close to what the customer originally asked for. On your vehicle there are a number of things that could cause the TCC to shudder. Some are as easy as an additive and some as difficult as a converter replacement and anywhere between. In this case the dealer was correct in suggesting they check it out for you. Ya see, they don't know that you actually know what you are doing, and maybe know even more than the techs in their own shop.

[TodFitch]

Greg's post supports what I am saying. There are a few guys in a dealer that know what is going on and it is unfortunate that they are not the guys to explain the troubles on a vehicle at first. And...when they are asked they try to be truthful knowing full well that their explaination might step on the toes of anyome who previously explained a problem incorrectly. Hoping that the customer doesn't say, "Well so and so told me this..."

Norm, To answer your question on the computer thing. You would be surprised how many people come into my shop and say to install this or that. If we just did that the vehicle may not be repaired. Then they point finger at the service people as the reason and want us to fix it with no additional charges. What we do is advise the customer that we can do as they ask. If it fixes it, and it might, great. But if it does not then the cost of diagnosis is theirs. They always ask, will that money from the original non fix be credited to the actual repairs? Like we do the work asked for then if it does not work they want their money back so they can do it right. We tell them no, it is a service and there is a price for that service and the repair is another service and there is a price for that too. The next thing is, if they say go ahead and confirm that what they wanted was right, they almost always say that why should they pay for checking it out when they already knew what was needed. I have to tell them that the gamble is theirs. Do they want the part replaced and see or do they want us to find out what really is needed even if their diagnosis is correct? Now, we use computers to look at the data stream and troube codes. We also use computers to activate various systems within the vehicle to see if the computer can command and if the item commanded will respond. You would be surprised at the number of times the actual fix is not even close to what the customer originally asked for. On your vehicle there are a number of things that could cause the TCC to shudder. Some are as easy as an additive and some as difficult as a converter replacement and anywhere between. In this case the dealer was correct in suggesting they check it out for you. Ya see, they don't know that you actually know what you are doing, and maybe know even more than the techs in their own shop.

I guess it goes both ways. I don't like it if I am treated like an idiot when I tell the service manager what I think is wrong. On the other hand I'd rather not pay for work that won't fix the problem.

I recall taking my 82 TC3-Turismo into the dealer when it was several years old and asking that in addition to the normal mileage service that they change all the belts and hoses.

About 3 weeks later I had a small hose that went to the firewall connection to the heater burst on me on the highway. Come to find out that it had not been replaced. When I complained to the dealer they told me that they did not normally replace those (even if explicitly requested) because "they don't fail" and "it is hard to get to".

Then there is the time in my 1992 Jeep where the dealer replaced the serpentine belt and adjusted it way too tight and I ended up on the side of the road with a water pump with a ruined bearing.

I guess anyone who has had dealer work done on a car has dealer stories to tell. And I guess those times that things were dealt with in a competent manner are quickly forgotten. We only remember the times when the idiot dealer people blew it.

[bob_amos]

Norm, That is a real instant diagnosis on your trans. GM has had this for some time and a diagnosis fee really isn't needed there. The solonoid sticks and the TCC lock up stays engaged and kills the engine. Kind of like stopping without pushing the clutch in on a standard trans. But, the gamble, again, would be yours. That is a gamble I would have persoanlly taken. The dealer as well as independant repair shop do generate income from diagnostic work so you can understand their desire to perform it. That along with the knowledge that the repair is done correctly. In a case like yours I still recommend a check out first as I want to assure that the computer has commanded the solenoid OFF. But that really does not happen often enough to worry about. Tell me, why didn't you just drop the pan and replace the item yourself? It's an easy buttimely job and you are capable of doing it. Just wondered.

Tod, You are correct in the point that if you request it then it should be done. PERIOD!! I'd say that the shop should have done as you requested. A hose is a hose is a hose and the all have a limited life span. Just because they are difficult to replace is no excuse to not perform the task. Hey, that is why it is called work.

[JerseyHarold]

Greg,

I did a lot of dealer swaps when I worked at dealerships years ago and then as an 'independent' to pick up extra cash. I learned the hard way not to trust fuel guages. I once took a new car to NYC from NJ, and stopped along the way to pick up the lot kid, who dropped an identical car at another dealership. The fuel guage in the car I was driving read half full. I happened to ask the kid why he put so much gas in this one, and he said he didn't put any gas in at all, because it was half full when it came off the truck. Just as he said this, the engine died and I coasted to a halt on the side of the East River Drive in Manhattan....not a fun place to run out of gas!

As far as driving for fuel economy is concerned, I've always been easy on takeoffs and braking, and get close to or above the EPA rating on our cars. I'll just cough up more money at the pump, like everyone else.

Harold

[55 Fargo]

I have the exact same Van, except mine is an 2005, it also has the 3.3 l engine, we too are not pleased with the gas mileage, I figure around the 20 to 22 mph per US gallon, doing 100kmh or 62 mph, on the highway........Fred ps we have the new 2007 Chevrolet Uplander vans there fuel economy seems worse than the Dodges, we have both of these vehicles at work.

[55 Fargo]

I believe that is correct under the Nixon or Ford adminstration, here in Canada we had speed limits of 70 MPH on our major highways at the same time, we did not go to 55 MPH nation wide as the USA did........Fred