Are the EPA Fuel Economy Guides reliable? I know that the large print City/Highway figures are an average range and can vary widely, depending upon optional equipment, such as axle ratios and tire sizes. However, I have always thought that the EPA ratings represented an accurate basis for comparison of one model against another.
In February I bought a 2004 Silverado with a 4.8L V-8, 4-speed automatic transmission and the standard 3.42 axle. The truck actually has more power than I will ever need and I thought that I might be paying for this extra power by buying more gas than a 4.3L V-6 would use. However, according to the 2004 EPA Fuel Economy Guide, this might not be the case. It appears that the 4-speed automatic transmission version of the
4.3L V-6 uses MORE gas than the same configuration of the 4.8L V-8.Model Trans. Engine MPG Average C1500 Silverado 2WD A-4 ..... 4.3/6 ..... 15/20 17.5 C1500 Silverado 2WD M-5 ..... 4.3/6 ..... 15/21 18.0 C1500 Silverado 2WD A-4 ..... 4.8/8 ..... 17/20 18.5 *** C1500 Silverado 2WD M-5 ..... 4.8/8 ..... 15/20 17.5 C1500 Silverado 2WD A-4 ..... 5.3/8 ..... 16/19 17.5 C1500 Silverado 2WD A-4 ..... 6.0/8 ..... 14/18 16.0
Apparently, the electronic 4-speed transmissions have become so sophisticated that they get nearly the same gas mileage as the 5-speed manuals. In the case of the 4.8L V-8, the 5-speed manual transmission appears to get worse gas mileage than the 4-speed automatic. According to the EPA, my 2004 Silverado with the $745, 4.8L V-8 option and the $1095, electronic 4-speed automatic transmission is the gas mileage champion of the entire 2004 Silverado line. (Of course, I didn't actually pay retail for the truck.)
If these EPA ratings are true, I don't mind paying more for the 4.8L V-8 and 4-speed automatic transmission because I will be getting about half of that money back when I sell the truck. It's also nice to have the extra power available when it is needed. The engine seems to loaf along effortlessly on level terrain and does a minimum of down-shifting on hilly terrain. During highway cruising in 4th gear, the engine doesn't reach 2000 RPM until the truck is going 72 MPH. I have gotten a 16.43 MPG average out of the truck with driving that consists of around 20% highway and 80% city. Considering that I carry a constant 900 pound load, this seems to be in line with the 17/20 EPA rating.
Has anyone else found the EPA Fuel Economy Guides to be reliable?