Re GMC/Chevy fuel economy

Can't say about the new trucks ... all I've owned were 70's Carbeurated 350 cid Chevy and GMC trucks. The best one was a '74 chev 3/4 ton 4-speed manual which would do 21 mpUSg hwy; the others were all Turbo 400 (no OD), they all had the 750 cfm Quadrajet 4-bbl.

The worst was my 77 1/2 ton which could still manage 19 hwy. City-only would run from 14 to 9 depending on the truck and the season. In winter you might be idling outside for 20 minutes every morning, and you don't shut down for a short stop. Usually 3:42 rear ends. A few had air, a few didn't.

Even though most of them were essentially identical spec'd ... the 1/2 tons were all Heavy Duty Emissions (6000 GVW or higher) so no cat just like the 3/4 tons, there was little variance between them. All the parts swapped with the only catch being a switch to Metric fasteners in '78, so you needed to re-use the bolts from the truck under repair.

So, it's not all about the driver or what the EPA sticker says ... with two apparently identical trucks my experience is you can't expect identical fuel consumption.

The two 3/4 tons were both about 300 pounds lighter than my current 96 Ram 1/2 ton, and the 1/2 tons about 500, but fuel didn't change much with or without a load, so I don't know what effect that would have in the real world. The current Chevys and Fords are no lighter than the Rams anyway.

The 96 Ram (5.2) is my first non-GM truck and I'm OK with the fuel consumption; my data shows a long term average of 10.3, that's mostly city miles in cold weather, a best of 13.4.

That is all winter driving since I've only owned the truck since fall, and winter here means you're on ice and packed snow at least 50% of the time. Only major routes can be expected to be snow-free all winter, and they can be frosted or iced even if cleared of snow; both of those conditions are way less traction than snow.

I would expect those numbers to improve quite a bit in warm dry pavement; far less idle time, way less straight-line tire slippage, more turning traction which means you don't have to scrub as much speed prior to a turn and therefore accelerate as much after. I think a summer hwy-only of 16+ might be possible.

If I could move the summer city up to 13 or so I'd say that was equal to the Chevy typical; but I don't see the same thing likely to happen with Hwy mileage. In comparison with other guys at work who own the Rams I knew I would be taking a hit there coming in, so no regrets.

 

if your worried about gas milage then you really shouldnt drive a truck cause it will nver be good.I have owned lots of trucks most got about 12 mpg remember trucks are made for work and hauling.

 

My old 79 blazer with full-time 4wd, 350/auto got 11 MPG. Didn't matter what I was doing, empty, towing a car trailer, (with a car on it) hauling a camper, people and gear, 11 MPG........ that was it. I did a 4x2 conversion on it, and I got...... 12MPG.......... sometimes.

 

Yeah, Blazers were always gas pigs. Not sure why. The PT Cruiser is marginal too (16.5 average, manual trans, and I usually shift directly from 3rd to 5th OD in the city @ about 30 mph. That helped to the tune of 1-2 mpg). Might be the shape vs wheelbase.

The Miata gets 35+ hwy at legal speeds ... 25 city or hwy no matter how hard I run it. Back when I only owned one vehicle the truck mileage was more important to me than it is now.

Usually the best Fuel Economy speed with most any vehicle is 50-55 mph steady. Hwy posted limit here is 70 so that takes care of that strategy. I pretty much drive at least 5 over all the time city and hwy. They won't ticket you here unless you're at least 7 over, usually you can get away with a bit more, up to 10 or so pretty much without worry. 20 kmH is 12.5 over, that's when the lights come on.

I keep forgetting to try the OD off trick. I'll have to start doing that and see. Isn't there a mod to make off the default? Is there a downside to punching in the OD at 70 instead of wherever it normally wants to come on?

 

Must have a lot of city driving on that Cruiser. My CVT PT Cruiser convertible averaged a little over 25 mpg, which I thought was too low. When I bought it I was expecting 30 mpg or so.

 

That's better than others who own the same car tell me, but it just goes to show there's a lot of variation.

EPA on my 01 is 18/24 and 20 combined, so 16.5 / all city / all winter driving on some sticky winter rubber is right on track to meet the EPA estimate once winter is over.

I'll have different tires on it in a few weeks, once the overnight low gets above 50F. All the snow is gone as of about St Patty's day, but lows are still around 30~35 and the winter rubber is nice and sticky under 45F. Continental ExtremeWinterContact's in 15" ... VERY good winter tire in case anyone's interested. Better than Nokian Hakkapolita's, Bridgestone Blizzaks, Michelin X-ice. The summer tires are 16" Michelins, although I might change from them when it's time; they came with the car.