tire tread type and FE
 

My 99 Silverado 5.3L (hardly a gas saver) came with Off Road tires on it. They are loud and vibrate alot. I figure they certainly cannot be helping my FE.

Does anyone know if a Highway tread would help FE much.

for the record
I currently get 15-17mpg.

Absolutely. In my previous Honda, I saw fuel economy differences of 5% - 13% among various highway tires, which meant some had lower rolling resistance than others. So if you go from an off road tire, which is almost certainly not a low rolling resistance (LRR) tire, to a highway tire, you should see significant FE improvements. And if you specifically select a LRR highway tire, the improvement should be even more substantial.

Check out the Nokian WRSUV to see if it's available in your tire size:
https://www.nokiantires.com/en/tire_w...?season=summer

It's a LRR tire. I went through 2 sets of Nokians on my previous Honda (not the WR). Great handling, long tread life, LRR. Best tires I ever used. If you buy the Nokians and inflate them to the maximum sidewall pressure (likely 44 psi), I'll bet you'll get 15%+ better FE than you are now.

The BFGoodrich Long Trail has a low rolling resistance and not very agressive tread. I'm pretty sure the greenseal.org report lists it as doing well. Do a search for 'LRR tires' to find it.

Michelins...XGT I think

I'd go with a Highway All-Season tire on a Silverado. Like beatr911 mentioned, the BFG Long Trails are pretty nice. I had them on my old S-10 p/u. They did loose traction rapidly when I was down to 5/32nds, however. The Yokohama Geolander H/T-S G051s are another nice choice, IMO. You may not be able to reap the full benefits that a passenger car would w/LRR tires....but its a good start!

LRR tires is a good start. but,even @ 5 or 10% gain, you won't see much in your FE w/ that vehicle.
look in the archives for truck threads. grill block, airtabs,driving techniques, etc will help you as well.

I put narrower tires on my F350, and it seemed to help about 1 mpg or so. The original tires were 265 75R16 BFG Long Trail. The new tires are Michelin 235-85R16 M&S tires. The new tires are a tad taller, just 0.3". They don't have a very aggressive tread, but they did well last winter. Never got stuck.

I'm going to northern Maine next week, off road. I hope they do OK on muddy and snowy dirt roads.

The knobby off-roaders generally have a high resistance. Comsumer Reports has the latest report on tire RR, but you have to pay to use it.

I have Michelin MXV-4 "Green-X" LRR treads on the 'Teg. Overpressure and this tread design really helped boost FE. Judging from my Gaslogs, I would say that it helped in the 5-10% range, plus or minus. They're a bit pricey, but I don't worry so much putting 50 psi in them. One-year of use and they're great.

Best FE...

RH77

glad i didn't mention acetone. <looks around for flying rocks>

anyway, there are things in addition to driver mods that MAY help.

as previously stated, "if something works for you continue using it, if not then stop."

never tested them. but, i can SHOW you that acetone,for example, DOES(my car) and DOES NOT work(wife's car). if you don't come see it, you'll have to take my word(tested #s)for it. or not, the choice is yours.

i understand your skepticism tho. i'm a "seeing is believing" kinda guy.

BUT, remember...don't believe anything ya hear, and only half of what ya see!

Yah, I'm a data guy too. The Scientific Method is too powerful to ignore.

Now, for the Acetone -- the application varies so much to the point of inconsistency. I'm not throwing rocks, just stating my case.

RH77

Back on topic a little...

Where would someone find a list of the rolling resistance of tires or a list of Low Rolling Resistance (LRR) tires?

Here's the Green Seal LRR tire compro test-thingie from a few years back.
it's a PDF file.

Thanks a lot. Interesting source.

https://forums.tdiclub.com/showthread...=147718&page=4

discuss

shun

Thanks for everyones input. Hopefully I will sell the thing before it needs new tires. I only drive it about 3,000 miles a year, so it is a good bet, but if not, I'll be going with a highway tread for sure.

Boeing 757-200
 

I had a nice 3-hour flight today with full view of airtabs in action.

For those aviation fans our there, here's the aircraft: the Boeing 757-200, 5500-Series on NWA. (757-251)

https://pic16.picturetrail.com/VOL698.../287638865.jpg
Courtesy Airliners.Net

As I looked down the wing at these 14 items, it became perfectly clear. Unless you plan on using the top of your vehicle as an airfoil, and you're concerned about losing lift when going up hill, then forget about it.

The link that Treb' posted made it plain as day. In aircraft, it holds the air to the top of the wing, using vertices -- shaking up the airflow so it "sticks" to the top, and the wing doesn't loose lift when tilted upward.

What advantage does this have in a car? It shakes up the air, and creates a disturbance at the rear of the vehicle -- an unwanted side effect of the average vehicle anyway. Mitsubishi did a test of it on the Evo-9, and came to an interesting conclusion (you'll still find it on the car, though).

Mitsubishi Test Article

If I'm missing something, let me know...

RH77