Hyper Miling. 118 mpg!!!

alfadriver wrote: In reply to Adrian_Thompson: Adrian Do the math on your commute. See if going 65mph in a 70 zone where you are doing 80 will do something that signifcant to your commute time. My leaving time has a LOT more impact on when I get to work than how fast I drive. And whether I make a light at the end of an off ramp can easily negate any time I spend at 5 over. And it's also interesting to see that driving a "right speed" in lights actually gets me through them at the exact same time as the people who jump them- they just spend time waiting as I roll up behind them. 6 of one, half dozen of another.

I agree Eric, the differnce in my commute of doing 65 instead of 80 is marginal. But the diffence to my commute casued by some one crawling away from lights, doing 1/4 mile coast downs to lights and 1/2 mile coast downs to freeway exists while driving 45 or 50 when everyone else is trying to do 60-70 will and does make a massive massive difference. The single most important thing in commute time is everyone doing pretty much the smae speed. One guy doing 15-20mph less causes a massive back up. As I say, I can make 3mpg difference (2-5mins) by driving cery cautiously but not impeding traffic. To truly hypermile and try and push my thirsty pig to 32-33 mpg would make me a road hazzard on Southfield road and freeway

Zomby Woof wrote:

alfadriver wrote: Also, for a really interesting Miata- I've considered a 1.6, with a 3.xx final (which I can't remember what will fit in the box), and a 5 speed set out of a late RX7 (again, that cross reference web page is gone). What that would result in is 1-3 would be really close to stock, 4th would longer by the 4:10-3.xx ratio, and 5th would be even longer since the RX has a very long 5th relative to the Miata. Long story short- accelerating to 70 using 1-3 would be virtually identical, but 70mph would be 3000rpm instead of 4000.

Lower RPM doesn't always equate to better fuel economy. I've tried telling the Metro crowd (and they're VERY serious about FE) that, but they've insisted on learning the hard way. They have some excellent final drive options and rarely does it make a positive difference in fuel economy. Typically it makes it worse. My Swift GT uses the same amount of fuel on the highway in 4th as it does in 5th (.75-1 vs 1-1) despite the RPM difference.

I'm glad you put the "doesn't always" part in, since that's the really important word.

In my Miata, I'm pretty sure the engine is well into the rotational friction being the problem over making the required torque- but that's going from 4000rpm to 3000 rpm at 70mph.

When you get into the range where your engine starts compromising combustion to maintain the power range required to maintain speed, that's where the lower gearing equation really becomes the discussion. Many engines have to retard spark at higher loads (especially at lower speeds), and at the higher loads, one also needs to run richer to keep the exhaust temps down. So if your engine gets off of MBT spark or LBT fuel because you are asking to to run an engine speed that it has to do that- those changes way out distance any losses due to friction or pumping losses, and higher speeds are better.

Most people know about pumping losses (it's always brought up to do WOT accelerations "rule"), and spinning (lower speeds are better "rule"), but few seem to know that if an engine has to run spark retard or enrichment- you really drop off efficieny fast. Very fast.

It's all very dependant on the engine. So no point in putting general engine speed ranges....

The Adirondack Motor Enthusiast Club held 4 Economy runs in 2008 and 2009.

Here is a link to a long thread on the runs.

Here is the results from one of the events.

We held these events early on a Sunday morning on secondary roads.

Mark.

gjz30075 wrote: I don't think I could stare at the back of a semi for any length of time. Unless there's other ways to achieve this.

Everytime I see this stuff, I secretly wish for a brake check on the semi trucks part....

I had a 83 Sentra wagon that on 93 octaine achieved 50mpg. Carbed 1.6l 5spd. I would love to find another but I haven't seen one for years. Mine was taken out by a caddy to the RR corner.

When searching the web for modifications for my car, somehow I always get a link to this site:

Ecomodder

There are some interesting threads over there, and a few things that I'd actually like to try.

I crawled up on a semi on my way home from work (when i had a job) one night and hit the fuel computer on the ms3. I saw it jump to 45mpg or so for a good 3 miles. That made me happy. Generally speaking I go everywhere as fast as reasonably and safely possible though- because I like to go fast.

In reply to alfadriver:

I'm pretty sure ive read that the biggest fuel hit is because a Miata computer goes "dumb" (cant remember which term is correct-open or closed loop) above a certain RPM. It is something like 3300 or 3800, but it definitely is below 4K. Keith?

MrJoshua wrote: In reply to alfadriver: I'm pretty sure ive read that the biggest fuel hit is because a Miata computer goes "dumb" (cant remember which term is correct-open or closed loop) above a certain RPM. It is something like 3300 or 3800, but it definitely is below 4K. Keith?

That's the same thing i fight with my MX6. Though.... on that car it seems to load AND rpm dependent. Sucks. I can GET 40mpg+ with it, but i can't really go faster than 75mph.

MrJoshua wrote: In reply to alfadriver: I'm pretty sure ive read that the biggest fuel hit is because a Miata computer goes "dumb" (cant remember which term is correct-open or closed loop) above a certain RPM. It is something like 3300 or 3800, but it definitely is below 4K. Keith?

No, it's not open loop at 4000rpm- that's easy to see that- the fuel economy drops off really fast when it's open loop. I'm getting 30mpg pretty easily.

To be sure, I could monitor it, since I have obd recorder stuff to use. I should hook it up and record my drive home....

The biggest fuel hit for Miatas is the driver- I see ranges quoted from 20mpg to 30. I'm at 30, and want to go higher.

Swank Force One wrote:

MrJoshua wrote: In reply to alfadriver: I'm pretty sure ive read that the biggest fuel hit is because a Miata computer goes "dumb" (cant remember which term is correct-open or closed loop) above a certain RPM. It is something like 3300 or 3800, but it definitely is below 4K. Keith?

That's the same thing i fight with my MX6. Though.... on that car it seems to load AND rpm dependent. Sucks. I can GET 40mpg+ with it, but i can't really go faster than 75mph.

Speed load and time. More modern enrichment system model temperatures, and enrichen to save them. It's legal to do component protection and run rich. And it's legal to run rich when the driver is asking for WOT. But just going rich based on simple speed-load- that's not really legal much anymore.

In reply to Datsun1500:

You could care less. Less enough to not even open this thread. But you do care.

You care enough to post that you don't care.

such a hypster you are.

I used to do this in Pittsburgh with my MINI Cooper S.

Basically only did the simple stuff that didn't cost anything... somewhat higher tire pressure, looking ahead to avoid using the brakes, coasting down hills, accelerating somewhat quickly, short shifting, not carrying a bunch of crap in the car, keeping the instantaneous mpg up, etc.

I improved my fuel economy from about 30-32 to 36-38. Even got 40 once from Pittsburgh to Columbus.

Just google it and read about different steps. It becomes a game, actually kinda fun.

A couple of years ago, I drove my Miata from the San Francisco Bay area to San Diego for the SCCA national tour. A group of 5 of us formed a caravan. One guy and his son were towing and enclosed trailer with their car in it. At their invitation, I tucked into the slipstream behind the trailer for most of the drive. I averaged 36 MPG traveling ~ 75MPH most of trip.

alfadriver wrote:

Swank Force One wrote:

MrJoshua wrote: In reply to alfadriver: I'm pretty sure ive read that the biggest fuel hit is because a Miata computer goes "dumb" (cant remember which term is correct-open or closed loop) above a certain RPM. It is something like 3300 or 3800, but it definitely is below 4K. Keith?

That's the same thing i fight with my MX6. Though.... on that car it seems to load AND rpm dependent. Sucks. I can GET 40mpg+ with it, but i can't really go faster than 75mph.

Speed load and time. More modern enrichment system model temperatures, and enrichen to save them. It's legal to do component protection and run rich. And it's legal to run rich when the driver is asking for WOT. But just going rich based on simple speed-load- that's not really legal much anymore.

80mph in 5th gear = open loop, regardless of load. (Obviously if decelerating from a higher speed in gear, AFRs are pegged 22.0:1, or if coasting in neutral, AFRs are about 14.8:1.) Any other scenario, and it's open loop, dumping all kinds of fuel.

I can keep 75mph in closed loop as long as i'm drawing a minimum of 10" of vacuum. 9" vacuum or less = open loop.

This makes going up hill on long highway hauls annoying.

alfadriver wrote: In reply to Datsun1500: You could care less. Less enough to not even open this thread. But you do care. You care enough to post that you don't care. such a hypster you are.

You don't think he meant " who cares about making all this fuss to increase your mileage"?

Of course he "cares". He just doesn't seem to think this efforting for a few more mpg is worth the trouble.

But you knew that already....

Need good gas milage? Get a 1st gen, 5spd insight and be done. Pay 0 attention to how you're driving, get 50+ mpg. Hell get a 92-95 honda Civic DX/CX and get diesel millage with gas prices! And never fix a thing to boot.

I'll draft on semi's, but not as close as a "true" hyper-miler will do, I despise tail gating. It takes my fat Subaru Forester from 25-27mpg to 30-32mpg if I can find a semi truck going ~73ish and park behind it.

stan_d wrote: I had a 83 Sentra wagon that on 93 octaine achieved 50mpg. Carbed 1.6l 5spd. I would love to find another but I haven't seen one for years. Mine was taken out by a caddy to the RR corner.

You might have been able to get better mileage with 86 octane.

The higher octanes typically have lower power density.

Rob R.

nymalo wrote: The Adirondack Motor Enthusiast Club held 4 Economy runs in 2008 and 2009. Here is a link to a long thread on the runs. Here is the results from one of the events. We held these events early on a Sunday morning on secondary roads. Mark.

Chang's CRX rocks! 118mpg :D

Hey, gas mileage is important to some of us! I bought a little Escort 33/50mpg because I was driving 100 miles per day in the city. Replaced a 22mpg Mustang...good call as I see it!

Swapped out the rear gears on my brothers 70 Mustang as he is prepping for a trip that will have him driving crosscountry TWICE in one month. A switch from an automatic with 3.70 rear gears to a T-5 with 2.8something gears took him from 17mpg to 28mpg.

Hypermiling is a precise science and lots of it does not translate to the real world well.

Bruce

Although I'm not a true hypermiler, I do post all my fillups on ecomodder, and occasionally strive to beat my last tank. I drive efficiently, but I don't do the whole engine-off coast and drive 55 thing(the stuff that pisses everyone else on the road off).

Compared to the EPA estimates for my car I have saved about 500 dollars in fuel over the last year. I see that as more money for autocross event fees, where I can bury the pedal to the floor and drive as fast as I want :)

I do find it painful to try and hypermile faster cars, the temptation is just too great.

LainfordExpress wrote: I used to do this in Pittsburgh with my MINI Cooper S. Basically only did the simple stuff that didn't cost anything... somewhat higher tire pressure, looking ahead to avoid using the brakes, coasting down hills, accelerating somewhat quickly, short shifting, not carrying a bunch of crap in the car, keeping the instantaneous mpg up, etc. I improved my fuel economy from about 30-32 to 36-38. Even got 40 once from Pittsburgh to Columbus. Just google it and read about different steps. It becomes a game, actually kinda fun.

This is what I am interested in. Mods that we can make to our cars and "reasonable" adjustments to our driving that don't interrupt the flow of traffic. I don't want to be one of the "dicks" as some one previously referred to the people obsessed with it. They are a hazard. there is a reasonable expectation as to how other cars are going to be driven. Courtesy and respect for those that you are sharing the road with is huge.

I guess I should clarify things. I don't condone hyper miling to the point of being obsessive and becoming a danger to others. However I can see it being a fun "game" to try and get better millage with your DD. Take my 924s as an example. It seems to get 20 MPG just about all the time. Except on track where it gets about 6 mpg. There has to be aero improvements I can make to the nose as well as the under tray that would help things. One of the biggest things I have found in my 924 is keeping the fount bearings adjusted properly. Other things I can see would be proper alignment and or an alignment that is geared towards better millage (less rolling resistance) and a performance based alignment. Since I have been meaning to install the MS home brew P&P in my 924s I am hoping that going to a more modern engine management system with wide band and a blended TPS/map setup it should improve things over the dated OE management system that uses a narrow band barn door AFM.

On the drafting of trucks. My expedition is effected the most by this of all my cars. However I always try to let the truck driver know what I was doing via the CB. I also ask what the condition of his tires are. Since a truck can not stop nearly as fast as a car if you are paying attention the risk of rear end collision is not as bad as tailgating a car or motorcycle. What really scares me about getting close to trucks are catastrophic tire failure. I have had it happen and it is quite spectacular as well as startling as well as in many cases some very large chunks of steel and hard rubber are sent flying.

Swank Force One wrote: 80mph in 5th gear = open loop, regardless of load. (Obviously if decelerating from a higher speed in gear, AFRs are pegged 22.0:1, or if coasting in neutral, AFRs are about 14.8:1.) Any other scenario, and it's open loop, dumping all kinds of fuel. I can keep 75mph in closed loop as long as i'm drawing a minimum of 10" of vacuum. 9" vacuum or less = open loop. This makes going up hill on long highway hauls annoying.

Well, for your car at least. Not all cars run open loop at 80mph. Just sayin.

A/C blasting, 65 mph in 6th gear, cruise control. 50 mpg avg commute for me without trying in a TDI. Hypermiling is for the birds.

wrongwheeldrive wrote:

nymalo wrote: The Adirondack Motor Enthusiast Club held 4 Economy runs in 2008 and 2009. Here is a link to a long thread on the runs. Here is the results from one of the events. We held these events early on a Sunday morning on secondary roads. Mark.

Chang's CRX rocks! 118mpg :D

That is the car I was talking about!!!! He drives his daughter to school in it just about every day.