I bought a small Chevy S-10 truck and would like to put tires on it that get better mileage.
This doesn’t have to happen right away as the tires still have plenty of tread.
I also want snow tires on rims for winter.
From what I’ve seen over the years is that auto manufacturers have put fatter tires on cars to make them look better and to improve stopping distances.
I really could care less about either so I would like to put narrower tires on that will roll better.
My tires are P205/75R15. What part of that number is the width?
If I put narrower tires on should I have narrower wheels?
I have time so I can search Craigslist to buy used.
Thanks!
Edited 11/21/2008 11:07 am ET by popawheelie
Replies
The 75 is the wide, the 205 is the tall.
Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations
They kill Prophets, for Profits.
205 is the width in mm
75 is the aspect ratio
15 is the rim diameter
I've had 195s on several S-10s
if you go any narrower, you'll need to up the aspect ratio to keep your gearing in the same range.
for more detail see
http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=46
Edited 11/21/2008 11:36 am ET by Ten_Thumbs
Try to go tall - that will lower your engine speed a bit at a given road speed. Lots of air, skinny tall tires. Don't worry about narrower rims.
LT tires may be taller than the equivalent passenger car tires.
You could go with 16" steel rims, if you could find some cheap - not a lot of variety out there in 15s anymore.
Forrest
I bought a small Chevy S-10 truck and would like to put tires on it that get better mileage.
This doesn't have to happen right away as the tires still have plenty of tread.
I also want snow tires on rims for winter.
From what I've seen over the years is that auto manufacturers have put fatter tires on cars to make them look better and to improve stopping distances.
I really could care less about either so I would like to put narrower tires on that will roll better.
My tires are P205/75R15. What part of that number is the width?
If I put narrower tires on should I have narrower wheels?
I have time so I can search Craigslist to buy used.
Thanks!
You'll need to plus size the ratios. IOW, a narrower tire of almost the same height would be 195/85r15. No, you shouldn't need narrower rims...but that depends on the rims you have now.
FWIW a 75 aspect ratio tire is already at the narrow end of the range.
Don't expect to see any noticable gain in mileage. The rolling resistance of properly inflated tires is a miniscule contributing factor to overall fuel mileage-let alone the difference seen in reducing it by 5%.
EDIT: McDesign's got a point about going taller reducing engine speed on the highway, just make sure you stay conscious of the speedo variance.
Edited 11/21/2008 12:31 pm by deadman1
Thanks! I'm not to concerned about the high speed gearing. this truck is primarily going to be used around town and it has a 5 speed manual transmision so I have a pretty high gear in fifth.
On the other hand, I don't want some low profile tires either. Stupid in my opinion.
The tires just look fat to me. If I'm going to be buying tires (and I will eventually) I want to get ones I like.
I don't want a taller or shorter tire. Just narrower.
I've been reading the link Ten thumbs posted.
to get a narrower tire with the same outside diameter, you have to go with a higher aspect ratio,
the aspect ratio is a ratio of how tall the tire is (from rim to road) to how wide the tire is. for example, a 75 means the tire is 75% as tall as it is wide.
If you went narrower without uping the aspect ratio, the outside diameter of the tire would be less, which could hurt mileage.
a 205 is not that big of a tire already for that truck IMO
very expensive for an absolute nominal return..
Your best bet is with proper sized tires inflated to the max recommended pressure.. that slightly increases the diameter and massively reduces rolling resistance..
If you do buy new tires look for those with the longest wear rating. that's an indication of hardest rubber compound.
Go to http://www.tirerack.com and check out the specs on every single tire made for that application..
I hear you Frenchy. I'm not going to buy unless it is just right. I used to throw money away on stuff but I think I have learned my lesson.
cars and trucks can be big money pits. The tires are fine.
I would like to get some snow tires on rims for this winter. From what i understand 2 wheel trucks need them.
again go to http://www.tirerack.com for snow tires.. best resource there is for any tires..
I buy them and mount myself save a significant amount over buying at a tire dealer. However if you don't have the equipment they will send to local installers just enter your zip code.. still a significant savings over tire dealers.
2wheel drive is problematic around here with realtively steep hills etc.. but your location could be differant.. if traction is an issue lower tire pressure untill the tires are squishy (around 20-25 pounds) weight is both a help and a hinderance. greater mass to get moving and stopped but better contact between tire and ground..
I like tubes of kitty litter where worse comes to worst you spread some of the kitty litter in front of where you're going. Always carry a shovel on snow days.. don't just shovel out the back tires provide a path for the front tires as well.
Thanks Frenchy. those are all great sugestions. We don't have steep hills in town and I won't be going far in the snow. So just a little help is all I need.
A couple of guys I talked to said getting going was the hardest. The rear wheels just don't grab at all.
So I was going to look for rear wheels and rear snow tires first. I won't spend very much.
Edited 11/21/2008 4:51 pm ET by popawheelie
My friend has a newer saturn car and the warning light went off that one of the tires was low on airI followed her to a convenience store and checked the air and I told her the tires are okay. I said they have 20 to 30 lbs of pressure. I said "don't worry about it"She called the saturn dealer and was told the tires are supposed to have 40 to 45 lbs of pressure.Does that sound right?."My wife ran away with my best friend and I miss him"
Some do need that.
As an aside..I rented a new 08 van a few weeks ago..as soon as I headed out in the AM it did the same thing , RR Tire Pressure LOW.
As it turns out, when you have a cold night , the pressure is indeed LOWER, but not always dangerous. Drive awhile and when they heat up, you are golden. Enterprise Rental filled me in on that lil tidbit.Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations
They kill Prophets, for Profits.
All 1's and 3's..how cool is that?Spheramid Enterprises Architectural Woodworks
Repairs, Remodeling, Restorations
They kill Prophets, for Profits.
I think you just won the grand prize."My wife ran away with my best friend and I miss him"
As another aside, did you know that those low tire pressure sensors don't actually measure tire pressure? It uses the ABS sensors to compare differences in wheel speeds. Apparently a deflating tire spins at a speed much different than the others.
As another aside, did you know that those low tire pressure sensors don't actually measure tire pressure? It uses the ABS sensors to compare differences in wheel speeds. Apparently a deflating tire spins at a speed much different than the others.
That depends on the Tire Pressure Monitoring System.
A direct(classic) TPMS, uses sensors inside each tire that does in fact, measure the actual air pressure in each tire. It then reports it back to a control unit using rf signals. They are very accurate, and in some cases, the system will actually display the actual psi per wheel.
An indirect TPMS piggybacks on the ABS system and tracks any consistant speed differential between wheels, and once that difference surpasses a preset threshold, will indicate a low tire. They are unfortunately useless until a tire is at least approximately 25% lower than the other 3(3 tires at 36, and 1 at 25), and useless again if all 4 tires have lost pressure(over time/atmospheric changes/etc.). Also, many vehicles use 3 sensor ABS(1-each front wheel, 1-rear axle), which negates the ability to monitor the rear tires.
There are also hybrid systems that mix and match, and systems like the H1 hummer that use air lines to measure/maintain pressure.
As hard as the NHTSA is pushing for them to become standard, the manufacturers are pushing to use indirect systems, because the ABS sensors/systems are already there and it would be therefore cheaper. Ahh progress...only if it's cheap!
That is not true on my Toyota 06' Tacoma.
The spare will set off the TPSM. It has a low psi sensor but does not tell you what the psi is.
Kinda like the low oil idiot light on the dash. Just letting you know that it needs to be looked at.
my tire sensor on my 06 tacoma are already broken, the light been on for 60k miles
The light comes on when a tire gets low. After you inflate the tire you have to press the TPSM reset button under the steering wheel column.BTW you should check out this site for 05+ Tacoma owners. It has a lot of good info on mods,TSB's and other stuff.http://www.toyotanation.com/forum/forumdisplay.php?f=61
My friend has a newer saturn car and the warning light went off that one of the tires was low on air
I followed her to a convenience store and checked the air and I told her the tires are okay.
I said they have 20 to 30 lbs of pressure. I said "don't worry about it"
She called the saturn dealer and was told the tires are supposed to have 40 to 45 lbs of pressure.
Does that sound right?
That sounds a bit high.
Take a look inside the door jambs or glove box for a GVWR label. It'll have the exact recommended tire pressures for that vehicle and those tires.
DO NOT just put the max psi listed on each tire. That is a required spec from the tire manufacturer for that tire, at it's maximum load... which is far more than they are currently carrying. All that is is the limit of it's capacity, not what's appropriate for the specific weight distribution on each car. The same tire brand/model/size may be used on 20 different vehicles, but each one has different load characteristics...and therefore different pressures to carry that load.
FWIW: Running them at max pressure may gain 1% better mpg, at the cost of braking efficiency, tire life, and ride quality.
EDIT: It looks like USAnigel beat me to the punch on a few points. He/she's right on.
Edited 11/21/2008 6:55 pm by deadman1
The only way to tell if it's right is to check the owner's manual or the sticker that's generally in the driver door opening.
The mark of the immature man is that he wants to die nobly for a cause, while the mark of a mature man is that he wants to live humbly for one. --Wilhelm Stekel
Wheelie, I have been driving a four wheel drive truck for a while now and find it fairly handy if I get in a situation with marginal traction.If I were buying another truck I would likely skip the 4 x 4 and put some sort of locking differential in a two wheel drive truck. I have no idea what it costs or how challenging it is to DIY but I think it would be adequate for me in all but the most extreme situations. I occasionally run across references to different types of lockers to retrofit on rear differentials and it seems like there are numerous options today.The main reason I would skip the 4 x 4 is to lose the extra weight the truck gains with the running gear for the front axle.Karl
karl please don't do that! (locking differential or positraction) on ice. A locking differential is positively lethal to all but the very most gifted drivers.. while it's wonderful getting out of mud and getting going under slippery conditions it's positively lethal on ice.
I used to believe the same thing myself untill I drove vehicles with positraction on ice.
what happens is the back wheels lock relative to each other and force the front wheels to go straight ahead no matter how you turn the wheel.. the only way to steer is a locking/ unlocking of the differnetial which may or may not happen if the road is slippery enough..
I could explain it in greater detail if you wish but you'd need to understand the differance between under and over steering and vector motion angles..
I now own 4x4 vehicles with open (unlocked or non-positraction) rear end. what happens then is in slippery conditions one front and one back wheel can provide the drive force in extreme slippery conditions which somewhat eliminates the rear end steering condition of a positraction.
Frenchy, You know more about the topic than I do but I had something along the lines of what Deadman refers to in mind. Actually the original concept that caught my eye was an AirLocker where you pressurize a line to the locker and it locks the diff up. That way you only lock it when you want it locked.Fortunately I don't have much ice to contend with so I didn't consider the issues you deal with.Karl
Frenchy, You know more about the topic than I do but I had something along the lines of what Deadman refers to in mind.
Actually the original concept that caught my eye was an AirLocker where you pressurize a line to the locker and it locks the diff up. That way you only lock it when you want it locked.
As far as selectable lockers go, I'd definitely lean towards an Eaton E-locker, as opposed to the ARB Air locker(or similar).
The air type lockers suffer from chronic leaks, and the electric are very reliable. They're similarly priced, both perform identically, and the E-locker doesn't require the on-board compressor.
toyota has a electric locker on the front of the fwd trucks, they make a cable that will replace the electric. The OX locker works this way too, one of the best. I have "Aussie Lockers" in front and back of my toyota but we never have snow or ice.
Yeah, electrics are getting more and more popular with all the ATV's using them too. The Ox Lockers are pretty darn bulletproof internally, but the cables can be problematic -not terribly, but the electrics are so damn easy.
The Aussie Locker is the same design as the Powertrax Lock-Right and Detroit EZ-Locker. They all work very well in street-off road applications...but I generally don't recommend them in front axles-that's where a selectable locker really shines.
Deadman, Thanks for the clarification on the lockers. If I had lots of free time and disposable income I would be putting an E locker on all our vehicles. I can't say I really need them but I love the concept.
When my wife bought a used 4runner she just missed buying one with a factory e locker and ended up with a different one with no locker. I can't think of anytime I (she) would have used it but it still seems like a great option to have availible.I bet Brownbaggs toyota with lockers front and rear can maneuver through some amazing obstacles.Karl
Like you said, a locking diff is great in loose conditions or mud. They are a nightmare on snow and ice until you learn what to expect and how to handle it. My truck came with an Eaton G80 locker as standard equipment. I want to say from the info I've seen that it locks when one tire is going 25 rpm faster than the other. The rearend kicks out to the side pulling away from a stop any time I'm on snow and ice unless I'm in 4 wheel drive.Interstate 80 and 50 mph is not a fun place to learn the characteristics of a locking differential. Front bumper in the left lane, rear bumper in the right, me sliding down the center lane, and traffic on both sides.
what happens is the back wheels lock relative to each other and force the front wheels to go straight ahead no matter how you turn the wheel.. the only way to steer is a locking/ unlocking of the differnetial which may or may not happen if the road is slippery enough..
The parking lot of our local Wegmans is VERY slick. SOmetimes in the rain the rear will lock but not unlock.
After a while you get used to a complete stop to get it to unlock............and if you forget? The front wheels turn but the truck goes straight.
That's why NOONE else in the house is alloowed to drive my truck unless it's dry out.
Try a Lock-Right active locker. They stay open until a certain amount of wheel slip is sensed, then they engage-similar to a posi or limited slip -only when they engage they are locked together, no slippage that eventually wears out and slips no matter what. On dry pavement, you won't even know it's there. In slop, you'll immediately notice the improvement. They unlock as soon as you remove torque, so if you hit ice -no locker again.
They run about $400, and are relatively easy to install. They just replace the spider/side gears inside the diff, so you don't even have to remove the carrier. I typically install one in about an hour, but I've done dozens -I'd figure 2 hrs for the first one.
If I were buying another truck I would likely skip the 4 x 4 and put some sort of locking differential in a two wheel drive truck. I have no idea what it costs or how challenging it is to DIY but I think it would be adequate for me in all but the most extreme situations.
I'm a two wheel drive, locking diff kinnda guy. Last 5 trucks in fact.
DANGER WILL ROBINSON, DANGER................
Most are set up to allow a certain amount of slip before locking up. What that means is that one tire will spin a little and then the rear will lock and put both wheels in action.
Almost without question, someone not used to this will quickly find themselves going down the road sideways in the snow, or rain.
I've found that about 300 lbs of sand directly over the axle, snow tires and a locker will get me the same places in snow that most 4X4's with open diffs will go.
BUT, and it's a big one..............it requires a differnet skill set that you will not develop over night.
One last note. I always buy my trucks new. The limitied slip or locking diff is a $250-300 option on a new truck but often comes with a lower ratio like 3.55:1 or lower.
You really do want skinny snow tires because they will cut into the snow rather than "float" on top of snow. I prefer studded tires , my driveway is a bugger.
I've heard that skinny tires do cut through the snow better. I've seen a trans am in snow with those wide sexy tires. Absolutely useless. He couldn't move at all.
But boy he looked good sitting there in the middle of the street.
The only reason I could see an advantage of using wide tires for me would be shorter stopping distance.
But i just don't get into situations where I do emergency stops any more.
I drive in the right lane and just about everyone passes me until we come to a light and then I line up behind them.
Most states have made studded tires illegal.. But yes they are a wonderful improvement.
I've heard the studded tires on cars diving by here in CO. I never saw them in KS or WI. I know they were illeagal in WI.
Edited 11/30/2008 12:01 am ET by popawheelie
Minnesota, the Dakota's and most eastern states. I would check carefully about Colorado. Studs really do tear up roads.
I will check before I buy. I hear them drive by and it sure sounds like studded tires to me. I wonder if the laws are enforced? Not that I'd go there.
Frankly I love studded tires.. we ice race with them here in the winter and at the end of the race some ruts are over 18 inches deep!
205/75R15
205 width in mm, 75 is % of tire height of the width, R is top speed rating, 15 is rim Dia. in inches.
Change the width and you should change the rims in an ideal world. The tire sits on the rim to give the best contact patch. Too narrow and the tread gets pinched, too wide and the side walls have problems.
Tire pressure should be set to the car/truck makers spec found on the sticker inside the door. NOT the pressure on the tire wall. This tire fits many cars/trucks and all are different.
You would be hard pressed to find a tire to give you a jump in MPG. Better driving actions would be a better way.
My F150 has had 4 different makes of tire and the mpg has stayed the same. But the best all round performing tires have been Continentals.
The "R" indicates the tire has a radial ply construction.
Your right, I was thinking pre 1991. Speed rating now comes at the end of the size rating.
http://www.discounttiredirect.com/direct/brochure/info/tmpInfoReadingSidewall.jsp
I think you will find that the "R" designation in a modern 205/75R15 simply indicates that it is a radial tire (as opposed to the old bias-ply or bias-belted tires). An "R" indicating speed rating would normally be at the end of the tire information. To see the various designations (as suggested by Frenchy) go to:
http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=35
(tire height/ actual rpm) X ( desired rpm / A)A= height of tire neededcross multiplylower rpm better mpg but too low hurt power worst rpmEdited 11/28/2008 8:36 pm by brownbagg
Edited 11/28/2008 8:37 pm by brownbagg
Just looked at what I have on the truck - 9.50-30-15 LT - on the tall side, not wide. Looks manly.
They've been great.
Forrest
The wheels should be marked with the rim diameter and width. Every tire manufacturer lists an accepted range of rim widths for a given tire. The specs they list for a tire are taken using a common rim size in the middle of that range.
When you're picking tires, look for some that are close to the same weight as the ones you have now (based on manufacturer info). On a 2005 Chevy Colorado 4x4, going from the stock General AmeriTrac TR tire at about 37 pounds each to Goodyear Fortera Silent Armors at 44 pounds each dropped my fuel mileage from mid 21s (sometimes 22+) to about 20. Tires were the only change - Driving style and normal cargo remained the same.
The tire pressure monitoring systems now required on new vehicles sold in the US were developed, in part, in response to the Explorer rollover crashes which were later blamed on failure of the Firestone tires that came from the factory. Its theorized that overheating of tires with too little air pressure caused the failures.
Interesting too that Obama made the claim at some point during the election that if every car on the road would maintain there tire pressure at recommended levels we'd save more fuel than would be gained through additional offshore drilling. Though many thought this was just campaign rhetoric I believe someone actually did the math and found he was right.
The tire pressure monitoring systems now required on new vehicles sold in the US were developed, in part, in response to the Explorer rollover crashes which were later blamed on failure of the Firestone tires that came from the factory. Its theorized that overheating of tires with too little air pressure caused the failures.
True on all counts. It's unfortunate that the rollovers were actually caused by Ford, but Firestone still gets alot of bad press from it.
SOme good responses all around,
A few words of caution.
This is a 4 cyl,5 spd truck you intend to use around town right?
75 is a pretty skinny tire by modern standards. With the 4cyl, and being used around town? Taller tires are harder to get rolling from a dead stop. Any decrease in engine speed will rather quickly be eaten up by the effort required to get them rolling.
Heavier tires/wheels (16")? Same effect.
Like Frenchy said, check out the tire rack. There are some tires made to last longer and some made to return better MPG, but you'll need to shop for them. They will alos be harder and offer slightly less traction, at take off and stop time.
In my opinion, you'll see better results by spending the money on: Fresh Trans, Diff and Engine oil, Fresh filters, New plugs and wires and routine maint, like keeping a clean air filter in it and making sure it's running well.
Just my two cents, take it for what it's worth and maybe ask someone with a 4 cyl truck who put those cool bigger tires on and lost 3 or 4 mpg
Thanks for the info comments. I understand how getting away from the tire size I have can be a mistake.
I'm not looking for a tire that looks better. I'm 52 and well beyond my wanting to look good.
This is my fourth truck and hopefully my last. If I get tires I need to bone up on what could roll a little better. I do know a bit about tires but have forgotten most of it.
I will go with the tire rack if they have what I want.
I've put a new air filter and changed the oil (synthetic) so far. I priced synthetic trany fluid at the auto parts store and am going to go by Wallmart to see if it is cheaper.
$15 a quart! Yikes!
$15 a quart! Yikes!
True, but remember............A transmission and rear end don't require such often changes.
I know. But I still think I can do better at Wallmart. I've made friends with the auto parts guy and go there for some stuff but for oil and filters I go to wallmart.
I plan to change all the fluids out to synthetic. Even grease where it matters.
The brake rotors are warped so I need to have them turned or replaced so i figure as long as I'm in there I'll re-pack the bearings.
I've never worked on rotors but the auto parts place can turn one for $15 or replace for $40. That sure beats the price my mechanic gave me. $ 300.
Edited 11/27/2008 4:25 pm ET by popawheelie
pop ........Buy new rotors and have them turned a 16 year old proved that rotors do not come allways without a warp from shipping. Ever wonder how your old rotors got warped?
I thought about that. It would be a good idea to at least put the new rotors on the machine and check them.
From what I understand cast iron can move after some time. I learned that from discussions about cast iron table saw tops. the best way is to cast it and let it age before machining.
From the pulse in the brake pedal they are pretty badly warped. I was going to take them in and see before I bought new ones.
The #1 cause of warped rotors is uneven and over torquing of the lug nuts.
And NO those special extentions the tire stores and mechanics use are not accurate. And YES you do need a good torque wrench.
Russell
I've heard that.
I plan on putting my own wheels on with my torque wrench.
That is absolutely true!!!!!! It is very easy to warp rotors....even on a truck. You should never let some guy at a tire store install your wheels with an impact wrench.
If you want to prevent brake problems....always use a torque wrench. I bring my wrench (set to the right torque) to the shop when I get tires and make sure they use it.
Other than changing tires, I won't let anybody touch the wheels on our vehicles.
I suggest making sure they are properly inflated.
- from the Office of the President-Elect, B. Obama ;)
"Preach the Gospel at all times; if necessary, use words." - St. Francis of Assisi
I'm not much help on tires but here is a video of cars doing wheelies
http://www.metacafe.com/watch/257411/car_wheelie/