Hi, Long Time Lurker
 

Hey guys,
I've been reading this forum for years and years, first couple posts here though. I aeromodded a few things on my 98 Ram diesel back in the day and was consistently getting 20-24mpg until I started modifying it. I did some minor stuff on my 2005 Avalanche, now I'm looking for bigger and better results on my new to me truck. My 2009 Avalanche has a 6 speed, plus it has cylinder deactivation so I'm hoping to at least get into the mid 20s. My drive home from where I bought it in Toledo, in total stock form I was able to get 24.5mpg (on the dash, not hand calculated). I'd be thrilled to get that every tank.

Already done;
Partial grill block

In the works;
Sail panel hole plug

In the future;
Cleaning up the underbody flow
Aerocap or tweaking the factory setup
Tune?


Thanks for the years of information and interesting reading.

Hi, and welcome.

I see by your garage ticker your ride posted over 20mpg, not bad at all for an Avalanche. You're on your way!

I'm sure you've seen it elsewhere, but the usual recommendations: read up on the 65+ modifications and the 100+ hypermiling tips.

The beauty of hypermiling tips is that a lot of them don't have much cost associated with them. We say that the most effective mod you can make is to "adjust the nut behind the wheel," it really holds true.

I won't be the only guy to say this either: Scangauge. The in-dash mileage display is good but if it's one of those that only shows you a rolling average, it isn't everything you could really use. If it provides instant MPG, the Scangauge is a much lower priority but still not a dreadful idea as its ability to display a lot more information gives you more ammo in your guns.

Without referring to the tips or mods, I have these two initial pieces of general advice:
1) Slow down. If you're keeping up with everyone else, you're getting the same lousy mileage they are. Don't drive like them and you won't get mileage like them. Okay, you might have to leave the house five minutes earlier.
2) Drive ahead of yourself. This is another bit of not driving like everyone else. The majority of drivers you see are really only aware of the vehicles immediately around them, and react to what those drivers are doing. With only a little practice, you can vastly expand your situational awareness to encompass the next several vehicles around you. Instead of reacting to what drivers adjacent to you have done, react to what drivers five or six or twelve cars ahead of them has done, so that when your adjacent drivers take action, there is already a slush space opening, or you have let off the brake, or swerved aside to allow the flaming oil tanker to pass, etc.

The biggest downside of this is that it tends to make you a lousy conversationalist in the car. If you like to talk to people while driving, expanding your situational awareness will distract you mightily from the topics at hand. On the other hand, losing track of the conversation is nothing if it means you get to dodge the flaming tanker instead of becoming one of its casualties.

I wonder how a SG will handle cylinder deactivation. Hmm.

And on that topic: do you have a dash light or some indication when you're in 4-cylinder mode? Like lean burn in a Honda, you will obviously want to aim to be in that mode as much as possible when cruising.

Welcome to the forum!

Welcome to the site!

Thanks for the welcomes.

Right now that's one of my biggest issues, in the 3 lane areas I don't really care if I'm going slower but in the 2 lane I feel like I'm holding traffic up. I often try to keep up with everyone until I encounter a good semi (nice low mud flaps, and not a damn gravel train that throws rocks and crap) and stay 75-100ft behind them for as long as I can. I'm amazed how much better mileage I get if I stay in someone's path of turbulence, beyond 100ft it seems to dwindle.

I actually have instantaneous mileage on the dash already, it's on the same page that says how many cylinders I'm using. When going 45-55mph I can stay in 4 a decent portion of the time... any faster than that and it only flickers into 4 while I'm coasting.

Does pulse & glide really make sense on an auto transmission? Also I was reading somewhere that people claim taking off briskly saves fuel, I can't imagine it. I'm sure the dash would read higher, but hand calculating...??

Post some pictures!

How hard you accelerate is really a per-vehicle measurement. Some respond best when babied, others do better when given a bit more welly.

Generally it appears the thrust is to spend less time in the low speed, low mileage regime. Go ahead and throw a few more dinosaurs on the boiler right now and get up to cruising altitude quickly, and you can then back off the power for longer and ultimately enjoy a lower overall consumption.

Hybrids are a special case: if the battery pack is in good condition, drawing more on the battery means burning less fuel to achieve cruising speed, at the cost of more battery charging on the fly. If you have some downhills to take advantage of however, you can get that energy back for minimal energy investment.

Regarding feeling like you're slowing people down: set the cruise control at the speed limit. No one gets to criticize if you're doing the speed limit, and the cruise control will not be cowed. It just goes. Yes, you take a bit of a hit in the economy by using cruise, but you may get it all back and then some if you can maintain a lower, more economical speed because of it. Lose some, win more.