Help... Only 10 mpg

[SilverSlug]

Ah okay I see. Either way, those numbers are incredible.

It would be really cool if you could track a few of the tank using Mileage Keeper or Fuely when you are doing city driving, even on mashing it in stop/go conditions.

[Davisca455]

Originally Posted by SilverSlug

Ah okay I see. Either way, those numbers are incredible.

It would be really cool if you could track a few of the tank using Mileage Keeper or Fuely when you are doing city driving, even on mashing it in stop/go conditions.

I can do that. It may take a week or two though to get thru a tank. Since this pandemic hit, the company has those of us that can, working from home.
I just don't drive every day any more.
But I'll go top off tank and note the odometer today to get the ball rolling.

Chris

[SilverSlug]

Originally Posted by Davisca455

I can do that. It may take a week or two though to get thru a tank. Since this pandemic hit, the company has those of us that can, working from home.
I just don't drive every day any more.
But I'll go top off tank and note the odometer today to get the ball rolling.

Chris

Awesome. I’m super interested at checking out the results.

And yes I’m in the same boat, don’t drive nearly as much as before the pandemic, working from home means M3 stays out way more.

[Davisca455]

SilverSlug,
I had to do a really small sample size of 38 miles on 3.4 gallons, because I have an hour and a half freeway trip I need to take.
11mpg, in town, driving like a total jackass.

[akkando]

Probably worth mentioning Arizona, California, Nevada gas will probably yield the worst MPG because of the special blend they have.

[SilverSlug]

Originally Posted by Davisca455

SilverSlug,
I had to do a really small sample size of 38 miles on 3.4 gallons, because I have an hour and a half freeway trip I need to take.
11mpg, in town, driving like a total jackass.

Hmm interesting, I wonder why the tremendous drop. Do you suppose the longer freeway cruises really affect the mpg that much?

[Davisca455]

Originally Posted by SilverSlug

Hmm interesting, I wonder why the tremendous drop. Do you suppose the longer freeway cruises really affect the mpg that much?

It's probably a couple of factors?
My trip to Olympia was 99%+ highway miles, plus all thru Oregon and Washington and back to California was on 92 octane fuel.
The last test was on California fuel and couple that with driving like a 17 year old in town (as requested) for that last test was probably a big factor?

Just got back from my trip to Sacramento this morning and topped back off.
72 miles on 3.8 gallons, so 18.9mpg.
The trip was a 90/10 mix of freeway/city.
Mostly between 80-90mph, A/C on.

[Scharbag]

Originally Posted by SilverSlug

Hmm interesting, I wonder why the tremendous drop. Do you suppose the longer freeway cruises really affect the mpg that much?

Oh hell yes they do. Cruising in 6th on the highway vs driving around town is a huge difference. HUGE.

[SilverSlug]

Originally Posted by Scharbag

Oh hell yes they do. Cruising in 6th on the highway vs driving around town is a huge difference. HUGE.

Indeed, but huge enough to result in 8 mpg difference?

[SilverSlug]

Originally Posted by Davisca455

Hmm interesting, I wonder why the tremendous drop. Do you suppose the longer freeway cruises really affect the mpg that much?

It's probably a couple of factors?
My trip to Olympia was 99%+ highway miles, plus all thru Oregon and Washington and back to California was on 92 octane fuel.
The last test was on California fuel and couple that with driving like a 17 year old in town (as requested) for that last test was probably a big factor?

Just got back from my trip to Sacramento this morning and topped back off.
72 miles on 3.8 gallons, so 18.9mpg.
The trip was a 90/10 mix of freeway/city.
Mostly between 80-90mph, A/C on.[/QUOTE]

Ok, so 90% highway here means that the mpg bumped back up to 18ish. Makes sense.

That's still very good. I dream of 18mpg.

[SilverSlug]

Originally Posted by Davisca455

Hmm interesting, I wonder why the tremendous drop. Do you suppose the longer freeway cruises really affect the mpg that much?

It's probably a couple of factors?
My trip to Olympia was 99%+ highway miles, plus all thru Oregon and Washington and back to California was on 92 octane fuel.
The last test was on California fuel and couple that with driving like a 17 year old in town (as requested) for that last test was probably a big factor?

Just got back from my trip to Sacramento this morning and topped back off.
72 miles on 3.8 gallons, so 18.9mpg.
The trip was a 90/10 mix of freeway/city.
Mostly between 80-90mph, A/C on.[/QUOTE]

@Davisca455 Thanks a lot for taking the time to gather these results. Very helpful.

Please let me know if you discover any other noteworthy data points.

[Scharbag]

Originally Posted by SilverSlug

Indeed, but huge enough to result in 8 mpg difference?

Easy.

Highway (140KPH in Utah) 11.5L/100KM (20.5 USMPG) with AC on and hot day

City (usually under 70KPH) 19-21L/100KM (11.75 USMPG) with AC on and hot day

These cars are absolute pigs. But they are very fun pigs.

Cheers,

[Davisca455]

Originally Posted by Scharbag

Easy.

Highway (140KPH in Utah) 11.5L/100KM (20.5 USMPG) with AC on and hot day

City (usually under 70KPH) 19-21L/100KM (11.75 USMPG) with AC on and hot day

These cars are absolute pigs. But they are very fun pigs.

Cheers,

Hahaha!
Well, I never really thought of the car as a pig, but when compared to a Sentra...you got me.
I guess how I always thought about it was "600+ horse power AND near 20mpg highway...that's right in the sweet spot for me!"
My '70 Buick Skylark (7.4L)...now that is a P-I-G!
That thing gets 6mpg going up the mountain and 6mpg coming down the mountain.

[RedScytheM3]

Originally Posted by SilverSlug

Indeed, but huge enough to result in 8 mpg difference?

Absolutely. Accelerating a mass from a stop requires much more work than maintaining the motion of the same mass. Go push a heavy box across the floor. You'll notice pushing the box from a dead stop is much harder than pushing the box once it's already moving. When most of your time is spent maintaining speed on the highway your average economy is higher because you're not repeatedly overcoming the resistance of a still mass

[Ashley_rj]

I have a harrop s/c m3 and I get about 20mpg most of the time. Mostly highway driving. Can use a couple of tanks in a day at the track though...

[SilverSlug]

Originally Posted by Ashley_rj

I have a harrop s/c m3 and I get about 20mpg most of the time. Mostly highway driving. Can use a couple of tanks in a day at the track though...

Very nice. Btw have you had your M in a dyno?

How much torque and horsepower are you pushing with that Harrop SC on there?

[jdamore]

When I put my ESS SCer on, the new injectors screwed up the mpg calibration (reads higher than actual). Because of this, I'm hesitant believe anyone with different injectors has an accurate mpg reading. Whether other kits are calibrated for the larger injectors or not, it isn't something I've looked into. Edit- I have zero clue how many mpg I get.. if the car is performing so poorly that it eats that much more fuel, I'm sure I'd feel it or it would throw a code.

[Ashley_rj]

Stock exhaust and 98 Ron fuel

[Ashley_rj]

Very nice. Btw have you had your M in a dyno?

How much torque and horsepower are you pushing with that Harrop SC on there?[/QUOTE]


It about 490bhp at the hubs see above

[SilverSlug]

Wow... That Harrop SC has a crazy steep torque line compared to ESS and others.

Very nice.