Gas Mileage

[baseball1]

I have a 93 suburban that sucks down the gas as we all know. Recently I lost mileage. It really started sucking it down. I went from about 12 or 13 to 8-9. Does anyone have a suggestion where to start? Thanks

[MT-2500]

Start with a good basic tune up.
Got any check engine lights?

[baseball1]

Thanks. I pulled a couple of plugs and they looked okay but I will change them anyway along with the wires. It has a new air filter. What else should I do?

[cwh13]

With an older 'burb I would look at replacing the o2 sensors. They can make an engine burn too much fuel as well. Replace the fuel filter as well if you havn't already.

[Legacy Man]

Wow, thats bad gas mileage! I used to have a 8.1L Avalanche that got that range of mileage but my 93 Suburban gets about 15 city and 19 hiway if I drive it like it has no brakes, ie. lots of coasting and pay attention to traffic flow and don't use the AC. If I start noticing mileage droping I change all my filters (air, fuel & oil) and run a can of BG44k in the gas. If that doesn't work then I know my daughter is sneaking the ol' burb out of the garage. Another thing, here in Denver, is that we have to run "Oxygenated fuels" during the winter months and that always causes poorer mileage. LM

[baseball1]

Thanks, I replaced the o2 sensor and it made a big difference. The old one was rusted and almost in two pieces. The local kid at the parts store said that it wasn't the o2 sensor if I had no check engine lights on. No light on and it was still bad. Thanks cwh13.
Legacy man, I have never got that good of mileage. I'll get 15 or 16 on the highway on a good day. around 13 in town. What is bg44k that you put in the gas? Thanks again.

[jtmarten]

From the BG website:

BG 44K® Power Enhancer®
BG 44K® Power Enhancer® safely, rapidly and thoroughly removes engine deposits in combustion chambers, intake manifolds, ports and on valves. It restores flow in fuel injectors and cleans the entire fuel system. BG 44K® Power Enhancer® improves fuel economy and reduces exhaust emissions. It restores that “like new” driveability to an engine’s performance and keeps it running better, longer and more efficiently. Add one can or bottle to fuel tank at fill up. Catalytic converter and oxygen sensor safe. NOTE: After cleanup with BG 44K® Power Enhancer,® regular use of BG Supercharge®II, Part No. 202, in gasoline engines or BG Diesel Fuel Conditioner with DPL, Part No. 2276, in diesel engines will prevent deposits from forming in the fuel system and upper engine for maximum driveability and fuel economy.

[cwh13]

Years ago I was told that Chevron Techron fuel injection cleaner is about the best fuel injection system cleaner on the market. I was told by an ASE mechanic to use it in 2 consecutive tanks. I was having a spark knock detonation problem on an '01 GMC K2500 HD w/8.1L that I owned. It also had a slightly rough idle. I ran enough to treat 25 gallons in 2 consecutive tanks and it cured both the rough idle as well as the pinging during heavy towing. I've used it exclusively for the past several years and have turned many folks on to it as well. This also may help your poor fuel economy.

Chris

[j cAT]

Originally Posted by baseball1

Thanks, I replaced the o2 sensor and it made a big difference. The old one was rusted and almost in two pieces. The local kid at the parts store said that it wasn't the o2 sensor if I had no check engine lights on. No light on and it was still bad. Thanks cwh13.
Legacy man, I have never got that good of mileage. I'll get 15 or 16 on the highway on a good day. around 13 in town. What is bg44k that you put in the gas? Thanks again.

the o2 sensors need replacing every 100,000mi. this is the replacement interval.....if this is not done you risk damage to your engine and catalytic converters, and as you found poor gas mileage/performance...


12-13 city and 15-16 hywy mpg is good......

[madeintheusa]

I just bought a '02 2500 4x4 with a 6.0 and 4.10 rear. I don't have it on the road yet. What kind of highway mileage can I expect on interstate at 65 mph?

Thanks

[j cAT]

Originally Posted by madeintheusa

I just bought a '02 2500 4x4 with a 6.0 and 4.10 rear. I don't have it on the road yet. What kind of highway mileage can I expect on interstate at 65 mph?

Thanks

if you have the correct truck tires you will get 14-15mpg max...the more the truck is loaded down expect less...