Myths about cruise control, highway speeds and mpg

[K5dreamer]

actually, on most modern cars by my understanding, engine braking uses NO fuel. when the engine is overdriving the trans the fuel pump stops supplying fuel, or the injectors stop spraying.

I could be wrong for a general statement, but i know for a fact thats how it works on my jetta. It has been verified with both vagcom software, and with EGT guages that cool down to ambient temp on downhill grades.

 

[us74k5]

oh yeah! well i got 49.6 mpg average driving my 2008 ford focus from Fort Hood, Texas to Fort Lewis, Washington. GoGo American cars!

 

[original balzer]

I got 138 miles out of 1 gallon of gas once in a full size chevy.

Bought the truck dumped a milk jug full of gas in drove it onto the trailer hauled it 138 miles home drove it off the trailer and ran out of gas in the driveway.

Does that count?

 

[blazin_blazer]

i have a 94 metro that just runs around town...the highway just winds that little 1L 3 cylinder engine up to tight...it gets hi 40's occasionally low 50's depending on traffic & how you drive it.

 

[blazinzuk]

Yah the old Metros ruled in the fuel mileage dept (the only dept they ruled in) It amuses me seeing claims of 30+ mpg being touted by smaller cars. We have always had great mileage cars but no one wanted them cause I guess there not as cool as hybrids. Mabey if they would have charged 20g for a Metro it would have made it cool

By the way K5 it was us gallons. Like I said it was a one time thing blew us away

 

[original balzer]

Ok my uncle had a little merc station wagon: topaz or linx or something like that. It was a diesel, I dont know how many liters. Anyway he bought it from a guy that was into little diesel eco box cars. He had several rabbits and simular. He had put a turbo on that merc wagon. It was still slow as tar but it got like 60MPG all the time. Me and my cousins used to fill the tank and drive around for weeks at a time. AND the tank was only like 12 gallons so it didnt cost much to fill it.

WE HATED THAT CAR except the fact that it was super cheap to cruise all over salt lake city, and could haul like 5-6 people.

Lot of memories in that car though, like the first time I smoked something other than tobacco, while listening to Becks song "loser" freaking out. But thats a differnt thread all together.

 

[K5dreamer]

yeah, mileage is one thing, being fun to drive is the other. The goal with my jetta is 0-60 in 7 seconds, and 70mpg. anyone watch top gear

the jetta is actually stylish, comforateable, smooth, handles well, and with the manual is actually pretty spirited to drive. I would never suffer through 90hp with a slushbox though.

 

[original balzer]

90hp? compaired to that merc of my uncles I bet your double even after the turbo. But the guy built it for economy, I rememeber thinking that turbo would fit on a motorcycle LMAO.

 

[6.2Blazer]

actually, on most modern cars by my understanding, engine braking uses NO fuel. when the engine is overdriving the trans the fuel pump stops supplying fuel, or the injectors stop spraying.

I could be wrong for a general statement, but i know for a fact thats how it works on my jetta. It has been verified with both vagcom software, and with EGT guages that cool down to ambient temp on downhill grades.

Yes, you are correct. I also know for a fact that many large trucks (class 8, etc...) use the same strategy now. We install a high-accuracy fuel flow meter into the fuel supply line and it will show zero fuel flow under certain conditions such as coasting down a hill. The first truck I saw this on we all thought something was wrong with the instrumentation or meter.