Gas milage

Hey guys, just a quick question.

I commute to/from campus every day, sometimes twice a day, about ~3 miles each way. This uses up gas, though I'm a bit surprised whenever one day it's a full tank and later (few days, a week, something like that) it's at 3/4 full or slightly lower. Probably not a big issue, though I'm just curious about some of the ways to help improve MPG. So far, I can think up of:

• Careful driving
• Regular maintenance (oil, etc)
• Properly inflated tires, maybe over-inflated?
• Depending on price, buy slightly more expensive 100% gasoline for power/dollar

Anything else I'm missing? When I do a quick, non-exhaustive Google search, most of the results are of the bogus conspiracy theory types like magnets and other nonsense.

 

Do a search for hypermiling...

I would not recomend using premium gas. Best tips are to slowly accelorate. Try to not go over 45mph. Try not to use the brake, i.e. when you see a red light try to reduce speed so that by the time you hit it, it is green.

I try to follow these steps and I can increase my mpg by 10%-15%. Over a tank it is like getting almost two free gallons of gas. One city streets I max at 45mph, even if the speed limit is higher. On highway I do 65mph, using cruise control. If I could hold it at 45mph my car would get much better mpg, but that is too slow for the freeway/highway/interstate.

Here are some more tips, which they say can improve mpg by 37%. How to Hypermile: 9 Steps (with Pictures) - wikiHow

 

Yeah your driving style alone can improve mileage quiet impressively. My car ranges from 22-28 mpg depending how many times that week I woke up late for work.

 

That's too short distance to be really efficient. You have a cold engine going both ways most of the time.
(I'm too lazy to look for a converter now but...)

My car (2.8/4wd) going to work and back every day uses 16l/100km on a ~5km one way distance. Doesn't matter if it's summer or winter or whatever. It's just like a cold engine with a choke on all the time. Any longer trips out of town and fuel consumption drops noticeably.

Speed affects too: at couple longer trips (both around 300km) I took, driving 80km/h speed fuel consumption was 6.9l/100km (winter) and another time at 120/kmh (summer) it was 10l/100km.

Basically, you need to move further away or take longer routes to achieve better calculated mileage. However the longer distance negates real-life savings there.

 

Most new car engines don't need to be heating up, myth dispelled.

As it's been stated, higher priced gasoline doesn't do much for normal cars, in fact it is a waste on most N/A motors (even high compression, direct injected ones). Slowdown on highways, go the 55 mph, you'll notice your highway mpg shoots up dramatically.

I'd say for maintenance, oil/filter is important, but also other things like spark plugs (inefficient spark plugs causes waste, and choosing copper ones that spark better can be good but they do need to be changed yearly vs platinum, iridium which last a much longer time), changing fuel filter (clogged filter can significantly reduce efficiency), changing the cap/rotor, even the injectors, servicing your fuel system is also important. Personally I Seafoam my car's fuel tank every 3 months.

 

I average 13.2 MPG, and I have no complaints. Just drive and pay for gas lol

 

I'd beg to differ, at least partially. They don't need to be warmed up for as long as in the old carb days. The bad part of the story is that it's the car that decides when it's warmed up and knocks the idle down, and not the driver.

The distance - or lack thereof - will be killing your gas mileage and there's not much you can do about it.

Air filter often gets overlooked. Don't follow that path.

If you actually have the option of buying a *real* 100% gas - and not just "premium grade" gas with 10% ethanol still in the mix - go for it.

Make sure your wheels are properly aligned and balanced.

That's all I've got for now.

 

Cars do run more efficient when warmed up. So one hypermiling trick is to combine small trips into one big trip. But it is true that cars should not sit and idle to warm up. As soon as you start the car, start driving. So it is true that they don't need to be warmed up before you start driving. In fact my 2004 told me to give it ten seconds, and my neices 2013 said drive it it right away. These were the instructions in the manual.

Oh, to clarify, when I said I drive 65mph on the freeway/highway/interstate, the speed limit is 65mph. And most do a lot more than that in my area. Also my car gear ratio is more efficient at 65mph than it is at 60mph. But the difference between 65mph and 45mph is about 20mpg, assuming I didn't have to start and stop. Driving fast just eats gas milage.

Try these habits for a tank of gas. I bet everyone notices the difference.

 

Thanks guys. I've been thinking about the 100% gas thing (yeah, it's actually the no-ethanol stuff, normal 87 oct, but that's fine since I'm just driving a family sedan anyway, nothing special). The energy density, from what I read, is considerably higher in 100% gas than a 10% ethanol mix, since ethanol has a poor energy density. I just need to crunch the numbers and figure out what price difference will it make sense to not buy the cheaper 10% ethanol mix.

Well, you drive a muscle car, soo.... Anyway, one day I decided to calculate my MPG after an aggressive Interstate/local highway drive (roughly 40/60) and I had ~17.5 MPG (my car's EPA rated for 20/29 city/hwy). Driving normally, I'm still probably within that range, though I haven't calculated any numbers yet.

Speaking of you and driving, I'll imagine that the drive up to Death Valley will be pretty boring/expensive o.o...

 

If I had the option - which is not available in my neck of the woods - of running my cars on 100% gas I'd do so 24/7/365. Ethanol is really not friendly to one's engine in the long run, and gas mileage would be the least of my concerns in that respect.