Highway MPG

[Rayme]

Ok, the reason that got my started this is all those people saying Camaro's/corvette/ big displacement engine gets good fuel economy on highways. Also dealers like to advertise the highways MPG, for obvious reasons of course.

I say it's all baloney! JEEZ!!!!!!!!!! It's easy to get good MPG on the highway, it has almost nothing to do with the engine. It's all in the final drive ratio, good tires and speed. Saying "get a corvette it can get 32 MPG on the highway with 350 HP" is terribly terribly misleading on how the "overall" MPG will turn out. It doesn't take einstein to realize after a couple read around here that most cars can go over 30 MPG just depending on how you drive it.

Manufacturers will start upping gear ratio and slapping on some LRR tires just to meet the new CAFE regulations, flipping the bird to city ratings. to keep their previous SUV's selling and selling the highway MPG to potential buyers thinking their SUV is actually good on gas.

Let's talk about the MEAT!!!!! City MPG, where cold starts, stop and go, frequent gear change and long idling actually hurt MPG. This is where a car shine, this is is "real life, under-the-city-EPA-rating" MPG everyday people get. This is where technology will shine the most (valve timing, cylinder shut down etc..). Give me a constant 28-30 MPG in the city and I'll be amazed.

Just venting off...discuss..

EDIT: Here's some MEAT CITY MPG

Toyota Yaris : 29
Honda FIT: 28
Mini Cooper: 28
Hyundai Accent: 27
Nissan Versa 5 speed: 26
Honda Civic: 26
Chevrolet Cobalt 5 speed: 25 (gained 1 city MPG after tweeks)
Ford Focus: 24
Chevrolet Aveo 5 speed: 24
Dodge Caliber : 24
Mazda 3 : 24
Volkswagen Rabbit : 22
Suzuki SX4 : 22
Subaru Impreza 2.5: 20 (****, look at what I drive!!!)

A little less shiny than advertised highway eh?

[Hateful]

I'm not really all that impressed with the advertised highway mileage.Most do no better than my Cavalier.

[theholycow]

For some people, city mileage doesn't matter because most of their driving is highway.

As for the VW Rabbit, I think that city rating is way low, and the highway rating (28) is too high. The close-ratio gearing is great for city driving and you can keep it under 1200 rpm if you want, and get 30mpg city. A normal driver just shifting at 1500rpm would get all the acceleration he wants and still get 27mpg city.

Now, I have no clue how they expect anyone to get 28 highway out of it with the largish-displacement engine and silly low gearing. A 2.5l 5 cylinder at 3000 rpm can't be very efficient, but it sure is lively!

[DRW]

I wouldn't mind seeing manufactuers up the gear ratio in 5th gear to increase FE. I think that's one of the advantages of the new auto trannies that come with more gears: they can add a tall top gear and still get good response since the trans can downshift when needed.

Manual trans drivers don't like to downshift on the highway to get power. They're too freakin lazy, so we all get trannies geared so low it's as if we're driving in 3rd gear all the time.

[Otistheminivan]

Well as someone that drives both of those big engine sports car. A Pontiac formula and Corvette. I race in a event that has us drive around the country. We coverd this yr 4400 miles in 8 days and 2004 with my Firebird covered 7800 miles in 9 days. The best milage I have to date on either car is just under 32mpg highway(75MPH Average). City mileage is 17-20mpg and the big one is race track milage is 5-6mpg.

So yeah they get crappy city mileage when driven normally. If you were so inclined could you get better mileage with hypermiling techniques yeah, but I choose not too. Let see Both of these car make just over 400RWHP. Both car capable of 170Mph Plus. I can cruise around on the highway without holding traffic up and get over 30mpg. What do you expect!!!!!

John

[96hb]

Well, the newer Vette's DO get pretty good mileage for what they are, and you look pretty damn cool driving one, too. I have been seriously considering buying myself one next year.

[Project84]

My '94 Camaro Z28 (LT1 6speed) does have some mods, computer tuning, full exhaust, bigger throttle body, deleted emissions equipment, and 160* Thermostat, but it was only able to achieve 23.x mpg on a 250 mile trip to Cleveland last summer. Granted, it was 95*F outside and I used cruise control nearly the entire way going 73mph, but I doubt even w/ extreme hypermiling you could put average LT1 cars into the 30's range consistantly. The cars just literally gulp fuel.

[palemelanesian]

Here's something to think about: The EPA uses 55mph for the highway test. The new 2008 test adds higher speed, but that's not used for the CAFE ratings. The manufacturers have no incentive to put taller ratios because they already get good numbers at 55. Who cares about 70mph?

[bowtieguy]

Originally Posted by Project84

My '94 Camaro Z28 (LT1 6speed) does have...160* Thermostat

can't you get a 180* or 190* thermostat? that would help some.

[GasSavers_RoadWarrior]

I wonder if there's a way you can have "diallable" spring tension on a thermostat... Turn a knob, it's 160* for the track, turn it back it's 210 for winter FE... turn it down to 200 maybe for summer... insulated knob of course, so if you start pinging going up a mountain pass in the summer, you can pull over and twiddle it.

Hmmmm have a spare thermostat housing... just wonder how I could tap a thread through it that would stay sealed...maybe braze a faucet/tap on top of it...

Anyhoo. Hwy mpg is quite important to me at the moment... I can get Marvin doing about 20 in the city though, and Wile-E could get 30 in pure city. A bump and grind commute would switch priorities of course, but then I might be considering transit or cycling, I recall 3 different "commutes" back in the day where it was generally quicker to cycle than drive.