See You In Hellbronze

Before I start my mini-rant, I'm no mechanical genius and none of my observations were done in any sort of scientific way, just that - observations. Anyway, on a recent trip to the Oregon coast my GTS averaged 20 mpg which I was pretty happy with considering it is a 17 year old V8 (18 years old if you count when it was actually built) designed for performance, with no 6th gear. I drove conservatively, kept it at 70 mph or slightly under the whole way, except for a couple times when I couldn't resist a burst of speed. We recently dumped our daily drivers and got new ones. The wife got a 2011 Kia Sorento V6 which maybe gets 26 or 27mpg on the highway, much worse in daily driving. I got a 2010 VW GTI which is better, maybe 30mpg, worse if you have any fun with it, but it is only 4 cylinders. When we were car shopping I was pretty much disappointed across the board with new car mpg. With all the new technology these days why is mileage still so poor? Is it the seemingly constant push for higher revs and more hp from smaller engines? Is it some kind of conspiracy between OPEC, the oil companies and the car makers? I guess we vote with our feet and keep buying the lower mileage stuff, and of course if I really wanted to save money on gas I could have bought a Prius or some other ultra-boring car. Any thoughts?

Mark SF

Generally car mpg has not changed much for several reasons. Although engines have got much more efficient, the efficiency has been used up by heavier and larger vehicles. Even my 2010 VW Jetta tips the scales at 3200lbs, not much shy of the 928. Also modern cars have more and more electrical devices which add to fuel consumption, and better performance which also increases fuel consumption.

Your VW Gti has almost the same performance as the 928, most of the same equipment, and much of the same room inside. It has lots of safety features like airbags, seatbelt pre-tensioners, stability control, etc. It does 30mpg instead of 20. Mostly thanks to an advanced, fuel efficient 4 cylinder. That's progress isn't it?

James Bailey

The Kia weighs nearly 3,800 lbs has a much larger frontal area so yes it takes a lot of energy to move it plus requires premium fuel also automatics are less efficient....But not to worry the Feds are going to fix it with NEW very high MPG fleet average fuel requirements.... The GTI is just a right foot problem

RKD in OKC

There is only so much potential energy available in a gallon fuel.

The internal combustion reciprocating piston engine is not that efficient to begin with and wastes a lot of energy. Just look at the heat it generates that does not make any useable power, ie. hot exhaust gases, heat taken away through water cooling, and even oil cooling.

anonymousagain

All the additional equipment, sound deadening, safety, etc, really adds to the weight. Still, those things can be overcome with better performance, both acceleration and MPG, especially with technology improvements. It's just not that much of a priority.

The problem is mostly cost adder. While we consider an additional cost of a couple hundred dollars to increase MPG without loss of acceleration totally worth it, auto makers cringe at that additional couple hundred dollars across the volume of vehicles to be made. Many times it's just a matter of QC tolerance acceptance; if built to a tiny bit tighter spec the results are notable...but the cost to build as such takes a hit and is undesirable for the target market. This is the majority reason why "supposedly" a person pays more for a Lexus than a Toyota or Acura than a Honda - QC is expected to be better and the consumer pays for it.

An easy example, Ford Taurus SHO, provides the same MPG as the standard model but with much better acceleration (2.5sec quicker 0-60). The problem is getting the consumer to pay the increased cost or rather price for that capability, in this example ~$15k !! Heck, that's the price of a new Fiesta... so realistically, one faster good mileage SHO or a slower good mileage Taurus AND a Fiesta. Tough Sell.

...now if someone would get rid of most of the bells and whistles and just build a functional car (forget about ratings to other brands/models), we'd end up with simpler equipment, less weight and less cost to be offset by better performance. Essentially create a new market niche for the performance/mileage vehicle that purposely skimps on "luxury items" to keep the cost down.

Of course, just my opinion.

inactiveuser1

New cars aren't much better but if you look at the turbo cars with way higher horsepower they get the same or alitttle better gas mileage but make 1 1/2 to 1 3/4 tiimes more horsepower.
Cars that have the turbos or superchargers are the ones getting the good gas mileage and putting out 450hp to 550hp which some of the 928's with superchargers may do the same way more power and still good gas mileage.

928GTSM

Well my 93 GTS manual has been fluctuating between 14.5 & 17.3 for most of the time that I've had it, running on 98 octane fuel at $8.24 a gallon (UK gallon is slightly larger than a US gallon). Attributing this to my driving style I recently went on a 300 mile round trip, predominanatly on main roads, and made a concious effort to keep my speed down. I set the cruise control at 90 mph and resisted the urge to acccelerate vigorously or go any faster right up until I was 10 miles from home where I had a couple of short bursts up into 3 figures. The result was the car returned an average of 21.4mpg, I was ecstatic even if somewhat bored.

I have a 2002 VW Passat 20V Turbo estate remapped from 150 to 220bhp and normal daily driving it returns about 24mpg and on a run just about 30mpg being half sensible but not overly cautious.
It seems that modern diesel engines are where it's at if you want good performance and acceptable economy. I'm currently considering a second hand BMW 535D Sport estate, 272bhp and driven half sensibly still returning nearly 40mpg!

BC

Its all the things mentioned above. But additional thought for today:

They are running these cars with VERY complex tuning profiles. Yes - at idle and at moderate cruise - they will use less gas than an older car - But power STILL needs fuel. And the tuning that these manufacturers are getting out of the SIZE of the engines is amazing. Remember that in 1993, there were no 3.5L V-6s from Japan or Germany in sedans making over 300hp. Now, there are. Engine size, weight, the usage of the car - all are variables. The 20-25 mpg range that the cars you mentioned get is probably a mix of sometimes getting over 30 or even 40 mph on cruise or light driving - and then getting under 15 or even 10mph when the tuning has the engine getting BUCKETS of fuel and air to create these high power smaller engines of today.

The S2000 that I owned before is a great example of this - without a cat - it smelled SO PIG rich that you could smell it idling with the top up. It was a 2L engine making over 230hp at 9000rpm or whatever - and it had WORSE gas mileage the way I drove it than a Corvette does on the city loop. I averaged 14mpg or so. 14! I get better than that in my wife's TL that is 7 years old and weighs probably 1000 pounds more. Its the WORK that I was asking the car to do - and that involves more than the weight of the car.

Today's enviro-***** want smaller and smaller engines. The issue is that people will not drive the cars that would weigh little enough to WORK with those small engines. Its simply not safe.

TOP gear did a sort of test where they had an M3 drive around a track behind (I believe) a Toyota Prius - the Toyota was to go as FAST as possible around the track and the M3 was to keep up. The test found out that the Prius was getting ABYSMAL mileage and much worse than the M3 because the Prius was WORKING harder, and the M3 was loping along at the bottom of its design parameters.

This is why a Corvette with a 6 speed can get nearly 30mpg on cruise at 80 and if you do 80 in a little buzz box, you may not get 28mpg.

BC

Of course, I have never gotten 20mpg in any 928 I have ever had. so....

tilac999

I get 15mpg locally and 20+ on the highway. Damn good, I think. Imagine if it had overdrive...

RKD in OKC

I drive my GTS like...well...Not a maniac, but I usually am the quickest away from lights, etc. and my dash says my average mpg is 14.7. My 92 Range Rover with 2.9 liter V8 gets a whopping 12 no matter what.

77tony

Just sold a 08 Corvette auto that had 436 H.P. with the optional tuned OEM exhaust and I was getting 27 highway. My newly acquired 94 928 GTS has 345 H.P. and gets 19mpg. Thats 8mpg more with the Vette with an additonal 91 H.P. Thats fairly significant. What are 400 H.P.+ 928 with turbos or superchargers getting. Lets compare apples to apples, in this case H.P to H.P.

jon928se

I used to get around 18 with my 92 Rangie with 3.9V8 - same with the 95 Disco -same engine same Trans.

I get about 15mpg around town in the 90GT. And I once got 28mpg on a 200mile run with cruise on for all 200 miles at about 83mph in the SE. IIRC that equated to the point in the fuelling curves where the SE was making the most power relative to fuel burned - about 2800rpm

By comparison the 1.5L Hyundai Getz only does about 20mpg around town with me driving and about 35mpg on a long trip.

pcar928fan

My wife drives a VW Jetta Wagon Diesel and gets 40mpg+ on the highway...that is AMAZING and the new ones (hers is an '05) do even better! A couple from Australia came to the US a couple of years ago and used an '08 (or '07) Jetta sedan and set a record (on a trip of 9,000 miles) of 56.4 mpg overall and then came back a year or two later with the next gen diesel Jetta sedan and upped the ante yet again to 67 mpg!!!! Same trip! That is STAGGERING really!

tmpusfugit

I find it interesting that some of the new "small cars" do not get better mileage than they do..... my wife has a 2008 Crown Vic 4.6 ltr V8 that we just finished a 3500 mile jaunt in.....air conditioner on for the whole trip, stop and go as well as a lot of interstate, often 75 mph+/-, average for the entire trip was 26.4 mpg. And the Crown Vic is not a small nor light car.

My last tank in the 84' 928 auto yielded 20.1mpg and it was running to the store sorts of miles, stop and go, with a couple of short runs on the interstate, and I tend to be a bit heavy footed...

My old Vette (86', auto) scores 28.5 mpg at 75+/- mph on the road.....

So why does my econo fartmobile with a 1600cc engine and half the weight only get 35 mpg when feather footed down the interstate with a tail wind?

And that diesel Jetta sounds like I should check it out.....I was recently in Franch and drove a Volvo 5 cylinder turbo diesel station wagon with 6 speed that did not sound like a diesel, ran like a scalded dog, relatatively speaking, and got some tremendous mileage, over 50mpg if I did the conversions correctly....