Ask MetaFilter questions tagged with car and gas

Automechanicfilter: The Case of the Thirsty Tank

desuetude — Sun, 22 Nov 2009 20:47:45 -0800

What could be some reasons why my gas mileage is very suddenly and dramatically craptastic? The decrease in fuel efficiency happened directly after I got stuck driving my car on a flooded road through deeper water than it should've been asked to handle. The car didn't stall, but it felt very close to stalling, and the steering was "stiff" for a few minutes. However, the functioning of the car returned quickly to totally normal. Except that my gas mileage is reduced by nearly half.

It's not running particularly rough or loud, using more oil than usual, running hotter than usual, or anything else that would signal an obvious "car is working too hard" issue.

The gas tank has been run down nearly to empty and filled, fuel injector cleaner has been used once. It's been a couple of months, so it's not resolving itself, that's for sure. And no, nothing's leaking when it sits.

It's a 1996 meticulously-maintained Neon. So yes, it's getting up in years, and I know that some cars lose fuel efficiency as they age, but this was a VERY dramatic change.

in cars

bunny hugger — Mon, 14 Sep 2009 11:35:19 -0800

I am disappointed in my relationship with my 97 Honda Civic. Maybe you can give me some advice. YANMM. I’ve tried to talk it out, but it's just not hearing what I'm saying... I've got a 97 Civic AT (106K mil.) and after filling up with what I think was some questionable fuel a while back, it has started to “slip” when I go into 3rd. It feels like something is "whirring" trying to find itself. Once past that bumpy spot, it runs great. I have had regular maintenance on it – flushings, fill-ups, tuneups, etc. I even added some Lucas transmission fix to my tranny fluid (which is pink and not burnt). Also, when low on gas, I have trouble starting it. Could it just be my fuel line, or is the transmission in the crapper?

Mythbust supermarket petrol for me, please.

Lorc — Sun, 30 Aug 2009 12:18:19 -0800

Is supermarket petrol bad for my car? It seems to be common knowledge that supermarket petrol from Tesco, Asda or what have you stations is inferior to the stuff from a "proper" petrol station. That it damages the engine in the long run for any of a variety of vague and poorly explained reasons.

Is there any substance to this idea, or is it just superstition? Googling gave me lots of conjecture but nothing authoritative.

UK-centric in case it matters. Thanks.

My 1994 Toyota Camry died while driving, any ideas why?

jackofsaxons — Tue, 23 Dec 2008 19:43:50 -0800

My 1994 Toyota Camry died while driving, any ideas why? On my way home from work my car died while idling at a light, and wouldn't stay running unless I kept the goosing the gas pedal. It also sounded like it was having trouble turning over when I as trying to start it again. To get it going again, I had to gun the gas and pop it into drive, and give it more gas than usual.

I'm going to have someone look at it but I was wondering if anyone could posit a theory on what the heck happened.

Radio on while getting gas safe?

alitorbati — Mon, 01 Sep 2008 23:47:15 -0800

Is it safe to keep my radio on while I refill my car's gas?

When gas goes above 4 bucks a gallon, it's the premium cars who hurt the most...

rileyray3000 — Fri, 22 Aug 2008 15:39:11 -0800

I want to use cheap gas in my 2006 Audi A4. Will this void my warranty? Basically with gas so high, filling up on premium is more of a pain than it used to be. I'm looking for any savings I can 30 cents a gallon difference in California wouldn't be bad. That said, I OWN the car and don't lease it so I don't want to ruin it. I plan on giving the car to my nephew when the warranty runs out in 2010 to be a cool uncle.

That said I would need to know

1) if it really hurts the car in any real way

2) If I DO use cheap gas, is there a computer or sensor doohickey that will tell the Audi people when I bring it in for scheduled maintenance

3) If they CAN tell somehow, will this void my warranty?

Any automotive or Audi experience will be appreciated.

Pro-ana car

speef — Thu, 31 Jul 2008 13:23:50 -0800

Car help: why can't i fill up my tank? (hint: it has nothing to do with the economy) I just got a 2002 Hyundai accent. I am enjoying the car very much, except one minor detail: I can't fill it up with gas.

When I try, the pump will say it's already full and stop literally every 1 or 2 seconds. I have tried not putting the nozzle in as far, not pressing the handle as hard, tilting it sideways, turning it upside-down, standing on 1 foot, etc. Sometimes my creative positioning results in a continuous stream of gas for as long as 3 seconds, but otherwise I just have to keep starting over and over. The end result is that I get 1/3 of a tank after 10 minutes of trying and then give up, crestfallen.

This is not a big enough issue for me to want to spend money on a mechanic (I'm poor and cheap), as, technically, I can fill it up with gas, it just takes 25 minutes each time. What I want to know is how I can diagnose/fix/improve this problem. (please keep in mind that I know nothing about cars; simple clear explanations with pictures are preferred)

Looking for a green family car

Reverend John — Thu, 05 Jun 2008 07:35:58 -0800

Help us pick a car! We're looking for a good used family car. We have two daughters, a 2 1/2 year old and a newborn and need a car that can accommodate an infant car carrier without putting the front passenger's knees in the glovebox. We'd really like something that gets good gas mileage and is reliable. We'd consider a hybrid, but its hard to find them (new or used) to test drive and check to see if the car seats fit well, and we're also a little concerned about the battery life on a used hybrid, as we've heard they can be expensive to replace.

A few more datapoints:

We really liked the Subaru Outback, but found its gas mileage to be a little disappointing. We also liked the Mazda 5 but were also disappointed with the gas mileage.

Can anyone suggest a used car with good fuel economy, decent room for the kids, and good reliability that we ought to consider?

Does this waste gas?

yellowbkpk — Wed, 14 May 2008 19:57:57 -0800

When I push the gas pedal on my manual car down beyond where it accelerates, am I wasting gas? If I shift early and end up on the lower end of my engine's power curve, sometimes I instinctively push the gas pedal down -- even if it isn't providing any more power to the wheels. When this happens, I imagine that the throttle actuator is squirting more fuel into the cylindars than is actually being burned, thus wasting some gas and dropping my gas mileage.

Is this true?

For what it's worth, I have a 2005 Jetta.

Tricks to get better MPG

raikkohamilonso — Tue, 29 Apr 2008 08:21:09 -0800

Simple tricks to improve MPG? For instance, I've thought about removing the rear seats/internal molding to lighten my car. I've also thought about aero-improvements, such as moon-disc wheel covers, or even somehow making a cover over my rear wheel wells. I'll be removing my rear wing this weekend, but what other tweaks could I do? Other things: sealing off the "styling" holes in the front fascia, slightly over inflating tires, etc...

Thoughts on possible bad gas - the car kind?

rainbaby — Mon, 18 Feb 2008 07:08:45 -0800

Bad Gas, the car kind, I think - advice? My 18 month old to me Newsed car, 17,000 miles, started knocking the other day. I got cheap gas a few days ago, and it's been wet, humid, and rainy. I thought I might have gotten bad gas. So this morning, with less than a quarter tank left, but before the low gas warning went on, I topped off at my regular station. Driving home from that, a warning light came on. The owners manual says this particular light is a diagnostic that could indicate a loose gas cap or bad gas, and if it stays on through a few normal driving cycles, to take it in for service under it's own power. It now occurrs to me that my instincts may have been wrong and I should have burned off as much as the alleged bad gas as possible before refuleing.

Any suggestions or alternate diagnosies before I call tomorrow for a garage appointment? What could I be looking at and what might the garage do?

Is it true that it is good for a car to fill it up with higher grade gas once in a while?

esolo — Sat, 22 Dec 2007 21:50:24 -0800

Is it true that it is good for a car to fill it up with higher grade gas once in a while? I usually fill up at Shell, and there is 87, 89 and 91 kinds of gas, with 87 being the cheapeast and 91 being the most expensive. I usually get 87. However, I heard that if you own a car and want it to last longer, it is beneficial to fill it up with the most expensive gas, to "clean the engine". Is that true? If so, what is the explanation behind it? I drive a 2002 Kia Rio, if that makes any difference.

how much money can I save by turning off air-conditioning when I drive?

esolo — Tue, 18 Sep 2007 13:25:37 -0800

how much money can I save by turning off air-conditioning when I drive? I know that turning on air-conditioning increases fuel consumption. How much money can I save per month if I go from using air-conditioning every time to not using it at all?

I drive a small 2002 car with 1.5L engine and manual transmission, and fill up my tank with 35L of gasoline twice a month. This costs me about $70 per month right now (Canadian dollars). My driving is approximately 40minutes a day, five days a week in the city.

If you could explain, how are the savings calculated, that would be great too!

Accellerate/Coast method more fuel efficient than cruise control?

Quarter Pincher — Thu, 14 Jun 2007 09:39:28 -0800

Question about cruise control vs. a special acceleration/coasting technique in terms of fuel efficiency. If you've got say, a speed limit of 45, and while driving on flat clean road, no wind aside from your own forward movement, etc, you accellerate to 47, coast until you're down to 40, then accellerate to 47, coast back down -- could this period of brief gassing up and long coasting by momentum, use less gas than having the pedal down the entire time and keeping at 45 (which I would assume cruise control would do)?

Would there be an ideal range (instead of up to 47 and down to 40, and back up/down) that would achieve greater efficiency? Would it be better to quickly accellerate to 47, or slowly (as the transmission gear may affect gas consumption)?

car gas diesel used

BigBrownBear — Wed, 06 Jun 2007 09:13:33 -0800

Diesel vs. Gas used car. Help me decide. We want to get a used car. I'm seeing some decent, not too old gas engine cars for 1000-2000 euros and some decent, not too old diesel engine cars for 4000-6000 euros.

I drive alot with work and find that when I rent a car, the cost of gas is significantly less with a diesel engine. But how can I better calculate the actual initial cost vs. ongoing cost saving? Does anyone have any experience or know any rules of thumb?

I know they're money-grubbing bastards, but would they stoop this low?

denimflavored — Tue, 09 May 2006 13:53:14 -0800

Who would I contact if I suspect a gas station has altered the pumps to give out less than a full gallon? The reason I ask is because I just filled up at a station for $2.79/gal (10-20 cents cheaper than everywhere else). My tank was close to empty, but not quite. It pumped 13.9 gallons, but my Civic only has a 13.2 gallon tank. Is it possible that my tank somehow deviates from the norm by over a half gallon, or is it likely that they have changed the pump?
I don't want to jump the gun, but at these prices I'm not very happy to be cheated.

Why does Wyoming have the cheapest gas right now?

p3t3 — Fri, 28 Apr 2006 08:51:54 -0800

Why is Wyoming the cheapest US state for gas right now and why does this map of gas prices look strangely similar to the 2004 voting maps? My initial inclination would have put Texas or coastal states near the bottom where oil is more accessible. But I'm sure it's more tied in to state/local economies and the demand/usage of gas in the region. But still, why Wyoming?

Questions about gasoline.

grateful — Wed, 26 Apr 2006 10:47:19 -0800

All about gasoline. (Apologies in advance on the two-fer.)

1) This morning, mrs. grateful accidentally filled up the tank with diesel instead of regular gas. The car stopped running, and she had it towed back to the station. They emptied the tank and flushed the system. Are there any long-term deleterious effects that we need to be concerned about?

2) In discussing the previous event, my father-in-law insisted that I could adjust my car so that it would no longer require premium gas. What adjustments is he talking about, and would they harm the engine in any way?

Should I warm my car up before I drive?

xoe26 — Wed, 11 Jan 2006 19:51:39 -0800

What are the advantages (if any) of letting your car engine run idle to warm up before driving? I've noticed a few people in my apartment block are starting their engines in the morning and coming back about 15 mins later. Why are they doing this? Isn't this just a waste of gas and bad for the environment.

Miracle car drives after it runs out of gas...or does it?

clgregor — Thu, 22 Dec 2005 12:30:33 -0800

What happens when a Hybrid car (i.e. Prius) runs out of gas? Can it keep driving on the battery? I see here that "The Asian and European versions of this vehicle provide a button labelled "EV" that maintains electric vehicle mode after startup, under most low-load driving conditions." But I'm in the US and I'm just windering how far I could drive after the tank runs dry.

Bad Gas Mileage

retro88 — Thu, 18 Aug 2005 12:53:38 -0800

Why is my Outback only getting 21 MPG! I recently bought a new Subaru Outback wagon that is rated for 23 mpg in the city and 28 mpg on the Hwy. I recently took it on a road trip and was not very pleased with the mpg I was getting. Both city and interstate driving were hovering around 21 mpg. I talked with the dealer and they had two things to say. One it is a new car and it takes time to “break-in” the engine to see expected results. And two, occasionally “flooring” it to get the rpm’s up will help break in the engine and clean out built up carbon etc.

My questions are, how long do I put up with this below expected gas mileage, is there anything I/or the dealership can do about it, and is “flooring” and driving it hard occasionally good for the engine?

Side notes, the car was moderately loaded (two suitcases and camping gear for two) and I had two bikes mounted on the roof (I know this would add some drag, but didn’t think it would be a noticeable difference.)

My previous car was an 95 Subaru Legacy Brighton, I was used to getting 24/30 mpg with it. It had a similar but smaller engine

Thanks!

Gas caps on cars - which side?

galto — Wed, 18 May 2005 13:01:10 -0800

Sitting in a car today as my friend was filling her tank, and my colleagues and I wondered aloud why there doesn't seem to be a standard for which side of the car has the gas cap on it. The car we were in had it on the right, as do both my cars, but the others in the car had cars with the caps on the left. What logic do car manufacturers use to determine from which side fuel is delivered? Some vehicles have the delivery point at the rear, and I believe I once saw a car with the gas cap near the front somewhere. Anyone know a rough ratio of left / right on North American cars? If there is a majority, is it an ergonomics thing? Just curious.

Bad Gas

mygothlaundry — Fri, 21 Jan 2005 12:06:56 -0800

Is there such a thing as "bad" gasoline and can it mess up your car? (+) My mother (age 77) says that there is, and that you should be careful to buy gas only from large corporate type places. I mostly buy my gas from the kind of skeevy independent convenience store on my corner, where it is incredibly cheap. My car hasn't been running well in some time (shakes, shudders, coughs) but then, it's a 7 year old Saturn with 135,000 miles on it. Should I switch to Exxon or something? Isn't it true that gas nowadays is much more tested than in the past and much more difficult to mess with? If the gas was bad in some way, than in what way is it bad and how did it get diluted/added to/whatever? My convenient gas seller has incredibly high numbers of cars going through there, it would seem difficult to adulterate the gas every day or something.