70 MPG US (3.3 L/100 km) challenge (non-hybrid gasoline and diesel cars)

[19bonestock88]

I’m getting serious about this, guys... in the prototyping phase on a couple different aero mods for the car... details in my build thread

[California98Civic]

Originally Posted by 19bonestock88

I’m getting serious about this, guys... in the prototyping phase on a couple different aero mods for the car... details in my build thread

Cool! I am at 69.9 displayed at half tank. I think the number is optimistic. Need some calibration.

[19bonestock88]

I don’t believe I’ll actually get a 70mpg tank that’s any real distance but that’s not gonna stop me from trying... on a side note, I’ve not seen record of even one other Saturn Ion that’s beating my numbers... duh, WINNING

[slowmover]

Originally Posted by Ecky

I'm taking a 4x8 utility trailer full of crap down to southern Vermont tomorrow. I bet I still get significantlybetter economy than your truck, despite being loaded infinitely higher than the car is rated for.

Loading the car to near design limits is part of operator skill. No matter the load, getting highest mpg relevant.

Empty, with driver, is like claiming the downhill MPG. Meaningless.

This truck is “rated” at 20,000-lbs GCVW. I’ve pulled trailers that — alone — weigh more than that. (That any commercial vehicle officer or station will pass as legal And insurance company is fine with. Commercial liability is in another galaxy compared to that for a personal vehicle ).

Does your loaded trailer weigh 2.5X as much as the fully-loaded tow vehicle?(past GVWR; relying on axle limits).

Published shipping weight at new was 6,860-lbs. Truck (solo) I can take it up near 11k.

The above combined rig weights were 32-33,000-lbs. The drivetrain had an “extra” 26,000-lbs to deal with. 3.5X empty truck ship weight.

That’d be for you, what? 10,000-lbs extra?

Given those max loads drop me to 10-mpg on highway (65-mph) on level ground with no adverse winds, are you SURE you’ve beaten me on a ton-miles basis?

3.5X the empty. Non-aero open flatbed. 60% fuel penalty

You might do okay driving my truck when solo (coming somewhat close to my numbers), but lacking experience with it fully loaded OR fully-loaded & pulling a heavy load, the POINT about the different conditions doesn’t change: Skill is highly dependent on experience. “You” (anyone) wouldn’t come close to 10 with those loads. Delivered on a hotshot schedule.

Load up your air-conditioned go kart and find THE OTHER END of solo operation as it will improve ANY OTHER CONDITION under which it’s operated. (Hell, it’s just training).

It’s flat fun to be able to glide along at max. Almost as smoothly. But the inputs to the vehicle are significantly different. (Now, add rain or snow).

But if this activates the special snowflake TILT-lamp warning & mind disablement feature, just forget it.

.

[mpg_numbers_guy]

Originally Posted by slowmover

Empty, with driver, is like claiming the downhill MPG. Meaningless.

Not really. Any downhill must be made up with an uphill on the return trip. Empty, with driver, can happen all day long on many trips, or for most of a person's driving with the vehicle. Meaningful.

All this extra weight stuff and whatnot is nonsense for the average driver. If I only need to tow 1000lbs, using an Insight will be far more efficient than an 18-wheeler, regardless of "miles per gallon per ton". If I needed to haul 100,000 pounds, the story might be different then.

Maximizing savings is not all about pure efficiency. That's why low RPM is better for fuel economy than best BSFC, which often is at higher RPMs on most cars. If, as in my previous example, one only needed to tow 1000 pounds, the most cost effective option would be the vehicle that could transport that 1000lbs at the lowest operational cost, not a vehicle that has the best "miles per gallon per ton".

Yes, you may say that you never specifically mentioned "miles per gallon per ton", but if that isn't what your point is in your post (and in most of your others), then I'm not sure what your point is.

[Xist]

In the words of Brian Regan's teacher, "You will always be wrong, no matter what you do!"

[Ecky]

Today I drove to Boston to drop my brother off at the airport. Before leaving I played with ignition timing a bit, actually retarded it a few degrees in cruising range to try and smooth out some lumpy acceleration. Knowing I'd be in stop and go traffic I pulled my grille blocks off, since the heat index was over 100 degrees and I've seen on rare occasion the radiator fan not quite keep up when there's no airflow through the grille in very hot weather. I never have problems in Vermont, but I'm considering replacing or "upgrading" my radiator so I can keep the grille blocked more.

Driving there at 65mph with some air conditioning for his comfort and just leaving it in 5th, plus driving around the city in traffic for an hour, I averaged 41.5mpg.

On the way back I decided to shoot for the moon and see how close I could get to my current "realistic goal with some additional modifications and a careful foot" of 60mpg, with my previous best being 48mpg. My target speed was 50-55mph except for where coasting would allow for higher speeds. My underbody paneling is around 50% complete, my mirrors are currently in place (not cameras), and I did not have my grille block installed. For around 20-30 minutes I drove through some heavy rain. For around 2/3 of the ~4.5 hour trip (~222 miles) I held the stick in 6th gear, which takes quite a bit of resistance plus concentration/finesse with the throttle pedal, as pushing the throttle past a certain point throws it out of gear with basically irresistible force (until I take the transmission apart and figure out what I did wrong to cause this). 6th would likely climb any grade without a problem, but it seems like it's maybe ~25% load that throws it out of gear. Anyhow, 6th is good for a reduction in RPM of around 25% over 5th gear. On some of the longer downgrades (more than 15 seconds where the slope could maintain speed or accelerate) I key-off EOC'd. I did not use air conditioning, and had the windows down around halfway.

I counted mile markets for 100 miles and determined my odometer error is currently at 1.2% (my current tires at 1.3% larger than stock). After 222.0 miles I filled up at a pump I trust with 3.40 gallons, resulting in a trip fuel economy of 65.3mpg. I'm stoked. It's not quite 70mpg, but I feel like 70 is really attainable on some trips if I get a real kill switch, finish my underbody paneling, put my camera mirrors back on, reinstall the grille block and maybe add a few more PSI to the tires, which are at 48 front 45 rear right now.

[Frank Lee]

How fast?

I have to putter along to get good numbers.

[Ecky]

Originally Posted by Frank Lee

How fast?

I have to putter along to get good numbers.

Can't believe I forget to put that in the post. I was between 50 and 55mph for most of it, aside from one brief throttle opening to embarrass a late model Mustang GT.

[California98Civic]

Nice numbers, Ecky. Thanks for posting. I am hoping to report my tank average tomorrow or tuesday. I am at about 70 mpg displayed. I adapted the calibration to make the display more conservative. Hopefully this is it.