NEW Hypermiling thread
 

Rather than just revive one of the old threads, I thought we might start one where we don't just share our triumphs (and frustrations), but where we share strategies, tips, and even what mods we've tried in the interest of fuel economy.

I know, going for fuel economy in an expensive, high-maintenance, 4500 lb truck seems a bit counterintuitive, but I see it like a sort of game :)

As long as you know your car burns more fuel if you put it in neutral while coasting down hills than if you just take your foot off the gas.

I'm in for curiosity sake. In the past, I've used elevated tire pressure and weight savings with a "stingy" driving style for some impressive results...

Or you can just go the diesel and get similar fuel economy to our previous petrol 4cyl sedan without even trying!

Unfortunately, we'd have to try REALLY hard to do that in an E53 up here. :(

Don't feel bad, people here make it hard to hypermile. Sometimes it seems like almost everyone here likes to race to red lights, stop at the green for no apparent reason, tailgate, change lanes without signalling, and brake hard going downhill instead of coasting... yet I am undaunted!
:driver:

I only avg ~13mpg in my Dinan 4.8iS so I have no idea what hipermiling is. :D

This is something I've always wondered about. So is the FIS injecting less fuel than what is needed to idle to bring down the rpms?

Also, a car going up hill in say 5th gear @ 2000 rpms @ 75% throttle. Same car going up the same hill, same speed, in 3rd gear @ 4000 rpms @ 25% throttle. Which one is getting better fuel mileage? My thoughts are if the car is FI, it would be the 5th gear and opposite for a carbureted car.

Any thoughts?

There are so many thoughts on this issue left over from the 70's fuel crisis (for all you youngsters that was when the Gov got involved in gasoline distribution as fuel prices reached ...gasp $.50 @ us gallon).
Best practices... Use the hills to your advantage. speed up on way down and slow down on way up.
Acceleration... Burns more fuel than anything other than a cold start up. Slow, easy, allowing the trans to get in to higher gear will give you all there is to gain.
coasting.... In gear or out of gear? Out of gear allows you to speed up with out engine involvement. You are left only with rolling and air resistance. The fuel is cut off when coasting in gear but the drivetrain will slow you down REAL QUICK.
Now the real questions should be "What is the wear on an auto trans when coasting in neutral, if any?"
For those of us who do not give a rats ass other than to say "hey, it is double digits!" I say hard acceleration is why we own the V8's with fat tires.
If you want fuel economy sell it and buy a 4 cyl whatever, with skinny tires and a manual trans. I personally use my Vespa to run to the post office and the bank. Early mornings only on weekend as I do not care to become a bumper ornament on a texting idiot's Honda.:wow:

Well said. Not into gas mileage, but curious. I love mashing the pedal and being sucked back into the seat as you blow by the guy in a raced out Honda who has all ready passed you three times! (That should of went in the "Ya Baby" thread)

At the moment I believe I'm right at 13.1 mpg and that's mostly city.

I average 18.5 liftetime according to the OBC with my '03 3.0 with 5-speed manual, and 20" staggered wheels/tires, which I know cost me about 1-2 mpg because of the weight. I run 33 psi front and rear, Toyo Proxes ST II tires.

When i calculated the last fillup manually (miles driven on the obc divided by amount of gallons filled up, I reset each fillup), I was at 18 mpg even. I drive mixed, about 60% highway and 40% city driving on a tank.

In my opinion not bad for a 3 ton SAV that is 10 years old, of course if i went back to factory 17s or 18s the mileage would probably improve but I love the looks of my 20s way too much.

Low rolling resistance tires make a huge difference- as does "over inflating" them... 50 psi was what I used to run on my Hondas. A slightly rougher ride but never had a issue... I agree with the above posts regarding hills- use the down hill to maintain or gas it a little so the next up hill requires less input.

Buy a Toyota Prius :)

^Nissan Leaf is better ;)

If you're going down hill coasting in top gear and keeping your speed, the FI is not injecting fuel. If you put it in neutral the FI needs to provide fuel to make the engine idle, then you'll need to brake to maintain your speed. Yes, lifting in gear slows the car down. Is putting it in neutral and back in gear at speed going to cause excessive wear on the AT? :dunno:

For my money, just avoid tromping the gas and unnecessary braking to get decent economy. Make sure your tires are properly inflated and get excess crap out of your car to keep the weight to a minimum.

One day I was stuck behind some turd in a Civic doing 80kph in a 110 zone and had a "Don't Honk I'm Hypermiling" sign on his trunk. I kinda wanted to punt him into the ditch...

Not sure if its a thing that is done/used in the US but here in the UK It is something that is commonly carried out to large engined motors and thats to LPG the vehicle, thats where the petrol fuel system is supplemented with a Liquid Petroleum Gas set up with 8 injectors mounted and a piggy back ECU that runs them and cuts the petrol out and runs solely on LPG and if the system is fitted by a reputable company you lose no performance and the only thing that comes out the exhaust is water vapor so its a super clean burn my oil changes (every 6k) the oil comes out as clean as when I put it it and thats no exaggeration.

I get around 18-19mpg with spirited driving but with the cost of LPG half the cost of petrol you are achieving a cost comparison mpg of 35-37mpg that makes running a big V8 cheaper than a 4cyl BMW sedan.

Yeah, a lot of taxi cabs here are LPG, as well as some pickup trucks. It's tempting.

No arm wrestle people but I have to be honest with you. I knew when I bought the X that it was an 8 Cylinder vehicle that begged to be driven. After all it is a BMW. So really why should I nitpick trying to squeeze the most MPG out every drop of fuel. I'm thinking just drive like someone with a brain and every now and then have some fun. The conclusion is.... LG.

Oh, if I had the 4.6 or 4.8 I wouldn't even try to hypermile. With the 3.0 I'm having fun with it as sometimes I get long stretches of 10L/100mkh on the gauge, and since I work from home (mostly) I'm never in a hurry to get anywhere. Of course, my right foot still gets heavy on the freeway now and then ;)

Like you say Professor "An intention without a decision is just a wish." I intended to buy a BMW, but I didn't wish to save fuel when I bought it. That to me would have been wishful thinking......;)

LOL

I've been watching football and trying to think of a reason that I would try this hypermiling in anything worthy to be on the road. The score is 13-7.

My best range on our '01 3.0, as I have posted a few times...wasn't really 'hypermiling', though conditions were very good: coolish temps for much of the ride, good humidity, traffic unusually light for this regular trip from NC to NJ to see DaKidz.

Filled up just across the NC/TN line, on cheap azz regular, and rolled into Magnolia, NJ on fumes ~9 hrs later: 568 miles.

I have done a dozen plus runs in the 550s/low 560s, and I don't set out to run that far without refilling, but this trip it just worked out.

Maybe the dead batt in my bird dog helped, as I was driving closer to the posted limit for the 5+ hour run north in the CopVille VA section.;)

Car was loaded as usual, but no extraordinary measures, and our 5 spd manual runs at high rpms at cruise speeds.
GL, mD

I averaged 25mpg on an all highway trip during the summer but it was very boring and cars passed me the entire time...I've found it gets the best gas mileage going 60-65mph in 5th gear at absolute minimum throttle. Don't try and keep your speed on the uphill and just let it go on the downhill. Unfortunately, in the city, I've found that you can't just drive like a granny and get good gas mileage...the stall is too high and it will just waste gas. Give it a good amount gas until you get up to speed and put it in 5th at all speeds above 30mph to maintain speed. I wish I got good gas mileage again, but I'm plagued with a check engine light as usual.

Highest gear with least throttle and Bob's your uncle.

Nice stats, mD. The lower speed helped a ton.

Factory highway mpg ratings for the E53 is what, 20mpg? Seeing a 25% increase of that is impressive ET- well played!

Even though our fuel costs more than in the US, there isn't a big financial prize in trying to improve mileage. But I consider it a personal challenge to drive smoothly and efficiently, especially on a long trip where I have a quantifiable indicator of that efficiency, and a so I always see what I can get on a tankful. The X3 has a 67 litre tank instead of the 92 litre tank on the E53. The engine is a 3.0, 265 hp. The vehicle is lighter than an X5 but has the same drivetrain. I try for 800 km (500 miles) per tank on the highway, and can nearly always get 760+. We just came back 1000 km today in snow, through the Rockies, temps ranging to -16. 780 km on the first tank. Should have used midgrade since there isn't a reason for using the premium in the lower ambients, but I used premium to minimize the ethanol contamination.

My quick calculations show that as 8.4 litre/100 km, 34 mpg Imperial, 28 mpg US. Not great driving conditions, and some traffic, heavily loaded with 3 people and luggage, so that didn't seem bad.

Running higher tire pressures increases tire wear in the center. I'm not sure the 1-2mpg increase would ever pay for the shorter lived tires, unless someone knows of some $50 tires I can fit on my Style 87's?

All my hypermiling is done in my Mini, or other previous commuters, and I could consistently achieve 3-4mpg better when I try to get better mileage than when I don't care and drive hastier.
Light foot, higher tire pressure (set to max load sticker on the door, not the tire), remove excess weight, change all fluids (brake fluid doesn't affect gas mileage though). Allow the car to slow down a little going up hills and speed up a little going down, trying to stay within a +-5mph range of the ideal mileage limit. Ideal mileage limit is generally different than the speed limit, depends on the engine and gearing of the car. The speed limit on my commute is mostly 55, but the gearing of my cars has proven that I get better mileage at 45-50 or around 60-62. 55 must be the ideal gearing for american cars?
And tailgating has always* proved to get better gas mileage because drafting means less HP is getting wasted on pushing the car through the air. Unfortunately, its somewhat dangerous, illegal, discourteous, and causes more rock chips and sand blasting of the front end of the car and windshield. So I reluctantly give up that extra 3-5mpg from drafting to protect my car...*always meaning when driving longer distances at a constant speed. If driving in stop and go traffic, tailgating will result in lower gas mileage. But trying to hypermile in heavy traffic is kinda pointless in the first place.

Once cars become fully automated (self-driving), we'll see tailgating taken to the extreme at highway speeds for the greatest efficiency. This also benefits the car in the front of the pack as they have less tail drag, although the cars in the middle of the pack still see the greatest benefit.

If we can end the forced ethanol 'enhancement' of our fuel, everyone's mileage will go up...I understand we can't just stop the subsidies, but we can stop wasting food to make crappy fuel.

So, to do this 'hypermile' thing, I need to invest in all new fluids, leave my family, spare tire and backseat home, have other vehicles up my a%s going up hill and be up theirs going down, tailgate incessantly like someone is towing me, break the law, chip up the front of my X, sandblast it where it isn't chipped, drive 55 on the freeway, quickly find two others going 55 and get between them--all so I might get 3-4 more mpg. Even my dog is not going to like this.

I don't mind ethanol. Though, getting rid of ethanol would be good, not for better mileage, using more Texas oil would increase the state budget for new roads like the new one with a 85mph speed limit--yeeeee-haa!

Since self-driving cars are on the horizon which means so is my suicide, what I am going to do is drive as fast and hard as I dare, hit the nitrous button as often as I can and not do any of that other depressing stuff. I will have lots of fun, keep my X nice and experience the best my X can deliver.

I do have a plan to save a wad of bills more than 2 or 3 'hypermilers' that I have to swerve around because they are going 55 when everyone else on 5 lanes of busy Dallas tollway is running along at 80 or more.

I will just drive, say, 200 less miles next year.

The best gas mileage I ever achieved in my 318i, back before ethanol was year round, was across Washington state over 2 passes and many hills, albeit with a tailwind, 38mpg @ 80mph. Seemed like the best gas mileage was around 75mph in that car. Of course, I don't think I ever drove it below 60...so who knows.

One more tip, don't slow down for corners, ever. that's wasting gas. in fact, I think going faster through corners may* actually increase gas mileage.

*gets you closer to the people in front of you for better drafting...

You guys crack me up. This morning I kept up about 8L/100km for a good stretch on the highway. No drafting, or extreme measures, just exploited every downhill. However city driving has me at 394km at 1/4 tank :(

So I also need to take 25mph corners at 55 so I can wear out my tires sooner, hear my wife scream, my dog yelp, have whatever is in the cupholders in my lap and draft the car in front of me like they are not going to brake for the curve---give up my supersize diet Dr. Pepper or suffer crotch shock, I would lose my Texas citizenship.

LOL... well, can't count this last tank, since half of it was on the old dirty air filter... topped off this morning and ready to make it happen. Was doing 28mpg most of the way on the highway this morning, at a blazing 90km/h hahaha.

I'll admit I got bored at one point and gunned it for a while to zip past all the ppl I was pissing off. ;)

Well, I guess we do have reasonable people who know what a waste of time this has been. Time to close this thread. :popcorn:.....:rofl:

Nonsense! I'm clocking 252km at 3/4 of a tank. That's 9.1L/100km, or 25.85 mpg.

:driver:

That 'stat' is of little value, imo.
Run a few complete tanks, usual driving, refill a few times, do the arith, see what that mpg number is, over a few tanks.

Yes, ~26 mpg via the OBC, for a stretch... With the 5 spd you won't see that often or over time, in my 12+ yrs of driving my 3.0 5 spd, under all kinds of conditions.

We'll see ;)

http://i.imgur.com/TMcSivp.png

Its a delicate balance of heat transfer, dP over the throttle plate and friction at speed. In general you would want to be between 2000 and 3000 rpm and at part load (30-60% throttle).

I get 600kms a tank
I drive all highway, 100kms a day @ 117km/hr cruise control
accelerate hard all the time

Just did a round trip, 850 mile run. Good conditions, traffic medium. Average cruising speed ~80mph ( with a few triple digit runs). I got my mileage to 15.6 per my obc.

Heh, that's pickup truck mileage! I'm at about 5/8 of a tank, 380km so far.

Well, so far, looks like I get a little over 800km per tank.

Per my post 23: 568 miles, best tank I ever got... :thumbup:
I thought you were raving about ~'26 mpg'? ;)

Ain't gonna happen over a tank or tanks.
GL, mD

I've regularly done the 1100 mile trip between Coppell, TX and Spring Hill FL with one gas/restroom stop, 60 miles to E showing on the OBC upon arrival. Actual calculated MPG of over 24 (GPS miles and gals pumped). OBC can be inaccurate.

This is done with the 255-18s all around (my hwy/towing tires, 38 psi pressure), under 75 MPH, following 2 seconds behind 18 wheelers when possible, no AC and windows/sunroof closed.

Stop and go around town I see around 420 miles per tank.

Well, I was doing about 28mpg for a little while... but the average so far has been 832km on 93.2L, which comes out to 11.2L/100km or 21mpg, though this did include 2 traffic jams and some very spirited driving.

I can get 800 km in the X3 on the highway, on 60 litres or so, with the 3.0 engine. Shows that you can't call it hypermiling in an X5.

Hypermiling...

I understand the def, but it is off the mark for most of us X owners, imo.

Few of us drive around with raw eggs under our feet, tires pumped to 45 lbs, skinny azz tires, coasting on downhills, sweating making the next 3 sets of traffic lights, etc.

Fwiw, that 568 I got on one tank was with 19" style 132s fairly wide azz tires, and making a normal haul azz one day drive from our NC Mtn Joint to NJ, to see the kids.

Just happened to catch a cool day with little A/C needed, until we neared the destination. Light traffic, no construction or accidents and few revenue cops for that 650 mile run...

Few of us are driving around in 5,000 lb cars chasing an extra 1/2 mpg to save dough or prove any point...I have more dollars than that under my couch cushions.

I do get a chuckle out of my Vette which can get 30 on some day long cruises, if I am lucky conditions-wise, and does do 28+ all the time on highway driving. But, weight or the lack of, and a very overdriven 6th gear ratio, coupled to a very powerful V8, are the key; not my 'driving'.

A shot I've posted before: a cumulative mpg shot after ~10,000 miles in a cross country trip. The arithmetic per tanks provided for a lower number of ~29+ at that time. I was not doing any 'hypermiling' at any time during that trip. :D

Back to normal driving and reality, here...
GL, mD

The sig Viper saw 26 MPG regularly, double overdrive 6th gear and 3.07/1 final drive ratio.