Herman and Operation 30MPG

[callahanoffroad]

Maybe I should be more clear on the goal. 30 MPG on the highway is the goal. When I started I was getting 22 mpg city and highway. Which told me something was wrong. Well maybe not wrong but strongly suspect. I'm aiming for 25 mpg city. Which I'm not very far off from.

FLXC90- synthetic oil will be in my next oil change. The place where I get my oil changed will be giving me synthetic for conventional prices bc no one uses 10w-30 anymore out where I live. Too many new cars using 20 weight oil!!!

After I get my 87 octane results from this tank I'll be exploring these two ideas:

1: Tire pressure and it's effect on mpg
2: Hypermiling techniques and their effect on mpg

Fun fact, when I shop for parts now instead of using '95 as my year I've been using '94 bc Herman has more in common with a '94!

I know most of this thread is psuedo-science, but I am trying to keep the variables down to one controllable variable at a time.

Abscate & rattnalle- I'm actually considering buying an '05+ p2 as my next car. My dad has one and it's really nice to drive.

[FLXC90]

My 98 S70 N/A gets mid to high 22mpg My drive is mostly city with a 5 mile stretch of road where I can stretch out at 65. Other than that stop and go not to exceed 45mph. All stock, leaking exhaust (but new O2 sensors ?!) and a drivers side axle starting to go.

Hopefully, I can swap out the axle (and lose the weight penalty of it being in my trunk) soon, then try a road trip for hwy. mileage.

Don't limit your synthetic to engine, go for the ATF also, that encompasses your gearbox, and your final drive.

[callahanoffroad]

My 98 S70 N/A gets mid to high 22mpg My drive is mostly city with a 5 mile stretch of road where I can stretch out at 65. Other than that stop and go not to exceed 45mph. All stock, leaking exhaust (but new O2 sensors ?!) and a drivers side axle starting to go.

Hopefully, I can swap out the axle (and lose the weight penalty of it being in my trunk) soon, then try a road trip for hwy. mileage.

Don't limit your synthetic to engine, go for the ATF also, that encompasses your gearbox, and your final drive.

Can you use Automatic transmission fluid in a manual transmission case?

Update: after running 93 octane, 89 octane and 87 octane there is no measurable mpg difference in my driving.

To sum up:
93 returned 23.98 mpg
89 returned 23.5 mpg
87 returned 24.01 mpg

87 turns into ~$0.09 per mile
93 turns into ~$0.11 per mile

Over 1000 miles
87 = $90
93 = $110
93 = ~19% more expensive to run than 87.
So that's some serious savings. Makes my "effective mpg" more like 28.56 mpg on premium. So now all I need is to find 1.44 mpg and I'm in business.

The mpg difference between octane ratings is negligable and can most likely be attributed to driving style through the tanks more than anything else.

As far as the power goes 93 seems to give a little more umph, but to quote my wife "if it was noticable you'd be whining about it."

I just filled my tank last night and I will be attempting to incorporate "Hypermiling techniques" into my driving routine starting today. So using lots of momentum, staying out of gear when possible, coasting as much as is possible etc. Sure, some pizzas might be late but science is more important right?

[Rattnalle]

Staying out of gear isn't always a good thing. In gear and engine breaking there's no fuel being injected at all. Coasting there's the idle consumption. Focus on looking far ahead so you can avoid changing your speed instead, it'll do much more.

[erikv11]

... Update: after running 93 octane, 89 octane and 87 octane there is no measurable mpg difference in my driving. ...

Don't forget to factor in the cost of a new engine, when it burns a hole in an exhaust valve after a couple years of running 87.

[abscate]

... Update: after running 93 octane, 89 octane and 87 octane there is no measurable mpg difference in my driving. ...

Don't forget to factor in the cost of a new engine, when it burns a hole in an exhaust valve after a couple years of running 87.

Buts thats on the next guy, if you time it right.

You could alternate between 87 and 93 and effectively burn 90 at lower cost than 91, Ive found by my pricing model in NY

[June]

... Update: after running 93 octane, 89 octane and 87 octane there is no measurable mpg difference in my driving. ...

Don't forget to factor in the cost of a new engine, when it burns a hole in an exhaust valve after a couple years of running 87.

If that! June

[callahanoffroad]

... Update: after running 93 octane, 89 octane and 87 octane there is no measurable mpg difference in my driving. ...

Don't forget to factor in the cost of a new engine, when it burns a hole in an exhaust valve after a couple years of running 87.

Just to make certain that I'm understanding your allegation correctly. Are you saying that bc 87 burns hotter than 93 it'll burn through the valves? That seems like a bit of a design flaw. Esp when they say 87 min octane.

I'm not trying to challenge you, but do you have any anecdotal evidence to back that up? I'd love to read about it. More info = more better.

Honestly I don't intend on driving this car longer than a year or two. It's already eating about 1 quart of oil per 1000 miles. I'm at 187,737 as of today. Not sure what point it'll need an overhaul but my last one died around 280,000 miles.

[Rattnalle]

If it uses that much oil it's been very badly treated in the past. Or something like the pcv is dodgy. None of my 300000 km plus cars have used more than a litre per 10000 km when I do the oil changes. They shouldn't need an overhaul before the rest of the car dies around the engine.

[June]

... Update: after running 93 octane, 89 octane and 87 octane there is no measurable mpg difference in my driving. ...

Don't forget to factor in the cost of a new engine, when it burns a hole in an exhaust valve after a couple years of running 87.

Just to make certain that I'm understanding your allegation correctly. Are you saying that bc 87 burns hotter than 93 it'll burn through the valves? That seems like a bit of a design flaw. Esp when they say 87 min octane.

I'm not trying to challenge you, but do you have any anecdotal evidence to back that up? I'd love to read about it. More info = more better.

Honestly I don't intend on driving this car longer than a year or two. It's already eating about 1 quart of oil per 1000 miles. I'm at 187,737 as of today. Not sure what point it'll need an overhaul but my last one died around 280,000 miles.

No design flaw. Look at your engines compression ratio which requires fuel that won't ignite by higher compression causing pre-ignition. Has nothing to do with burn temperature. 93 gives more ump due to the computer retarded the timing to prevent engine dammage. Look at octane of diesel that ignites by engine compression no spark plugs at all. So lower octane fuel is fine for engines with lower compression where higher octane is required for higher compression. It's a scientific fact. June