Scraped bottom on a speed bump - now MPG is suffering.

Well hold on now... lets not get ahead of ourselves

 

So your mudflaps hit...?

 

Dis

 

Not winter gas, but different local fuels. Different areas have different fuel blends. Give it a tank or two and see what happens. We got some bad fuel on the motorcycles recently and lost 5 mpg for a couple of tanks.

Howard

 

This, those things get hung up on everything. And I am with whipper on the winter mix part, it is about that time of year. I am not entirely certain what they do to fuel in winter either, but I think they add special additives to keep it from freezing in your fuel lines or something. These in turn make mpg go down somehow.

 

The mud flaps are hard plastic, this is very possible.

IIRC its an anti-freeze additive. More glycol based then ethanol

Your my god damned hero.

 

Ethanol stores 90% as much energy as gasoline by volume, so at a 10% mix, E10 stores 99% as much energy as straight gasoline. By example, that means dropping from, say 20 mpg to 19.8.

Winter gas is more about ease of starting than about keeping water contamination from freezing into ice. Take your summer gas down to -30 degrees, it has a lower vapor pressure, i.e., lower volatility, and much more difficult to ignite. Manipulating the fuel to increase the vapor pressure is done to make it easier to ignite the fuel while also maintaining an acceptable "at temperature" tendency towards ignition. That is an important balance, because otherwise, when the engine warms up, it would start into preignition.

So what they effectively do is alter the fuel to use a higher portion of smaller and more volatile hydrocarbons, which store significantly less energy per unit of volume. This has far far more effect on the fuel consumption than the ethanol content.

 

To close the loop on this (because I like to finish everything) - the winner of the "Tacoma Scrape Sweepstakes" is....


Pugga. He was right [first] - It was the goddamn mudflaps.

Thank you everyone for the suggestions and insights. This is a great community and I'm happy to have stumbled upon and become a part of it.

 

Haha

You're banned

 

This is what I'm thinking..

Also OP, what is the difference in your normal driving conditions vs the road trip you went on? These can certainly change things up.

 

I subscribe to the scientific method - so take this with a grain of salt. But the road down to VA I got 18 mpg (all highway) using RI gas; on the way home to RI (all highway again) I got 16 mpg on gas. I use cruise control ~74 mph all the way and maintain as I usually drive at times with no traffic. What the group consensus of "winter" or regional gas would make sense.

However, before I definitely say that this is the case I would want to repeat the same conditions on my next trip; however, if RI switches to their "winter blend" before Thanksgiving (which is probably likely) I wouldn't be able to test.

THAT, and I'm way too deep on something so trivial at this point

 

What did I win?

 

Respect, Pugga... respect.

 

word

 

Welcome aboard wh013mi1k! Yep those @&%$# mudflaps are way too low. Alot of guys here either take them off or trim and inch or two for more clearance. As far as your mpg i was wondering...between your test trips is there much elevation difference?

 

Geez, it's so simple. Going to VA you are headed down, to RI you are headed up. Look at a freakin map.

 

Negligible. The area of VA I head into is just outside of DC - too far east to hit the mountains. Plus, I would argue that it would be equal both trips as I take the same route down and back.

BUT, for arguments sake the elevation of RI is 200ft+ and the elevation of Vienna, VA is 358ft+. If the Tacoma is impacted by that small of a delta then I chose the wrong truck to purchase....

 

You go girl!






















Yep mud flap then winter fuel.

 

So quick update - I finally finished up the tank of the "winter blend" and decided to put in a tank of 91 due to some reading on this forum. I have only used 87 for the 2 months I've owned it - but noticed something peculiar....

Ever since I bought it new 2 months ago I've noticed that my second gear (auto tran) hits hard and has noticeable shudder between 15-20mph - nothing that made me think something was wrong, but it definitely got my attention.

HOWEVER, with this new tank of 91 octane the shudder going into 2nd gear between 15-20 mph is completely gone. Not even the slightest jiggle.

Does this even make sense?