Wheels and Oil

[BMRCRZ]

Hello Forum, I have posted here once before and got some great information in response. I think I might have pulled a couple brain farts here and was hoping to get some opinions. I purchased my M3 about 8 months ago as a second driver, and have only put a few thousand miles on her.

First, I was recently driving and remembered that I needed to add oil (I am aware that these engines burn oil) so I purchased the oil and added it right to the engine without allowing it to cool. Now sometimes I have a hard time heating the engine to temperature (granted, I live in Colorado, but only drive it when it is nice out). Am I overthinking this, or could I have caused a problem?

The second question I have has to do with tire size. I know the typical tire size for the front is 225/45 R17 and rear is 245/40 R17. I am about to need some new tires and I was looking at mine and realized that the rear are the same size as the front. Is this typical? Do I need to used some sort of a spacer if I have a flat tire? Again, Im not sure if I am overthinking this, but any information is greatly appreciated.

Thanks

 

[Big Daddy]

Hello again, adding oil to an engine hot or cold would not affect it's operating tempature, you are correct, you're over thinking! Check your thermostat and cooling system.

As far as tires sizes I do not know what year M3 you purchased but the early ones did not have staggered sizes. My 98 M roadster has stock the 225/45ZR17's on the front and 245/40ZR17 on the rear, however I have gone to 255's in the rear. I was told that I could go as big as 275 in the rear, but than you throw things off. The best guide is to go to the Tire Rack or Discount Tire web sites and enter your car information. They will tell you stock sizes and "plus" sizes that keep things in balance.

 

[BMRCRZ]

Thanks for the clarification on the engine temp. I will check into the thermostat and cooling system.

I believe the stock tire should have matched your 98 M roadster because my M3 is also a 98, and that is where I am concerned. It seems that the rear tires are too small (narrow) and dont match the stock information. Is there a spacer that is placed on the rear wheels that allow a smaller width tire (such as the spare) that I need to put on?

Again, thanks for the quick reply.

 

[Big Daddy]

The M's, at least the roadsters do not come with spares. If you have a 98 M3 you should have a staggered setup, I believe 8inch wheels in the front and 9.5's in the back. The offset should be obvious, if yours does not than someone has switched them out.

 

[jrt67ss350]

The M's, at least the roadsters do not come with spares. If you have a 98 M3 you should have a staggered setup, I believe 8inch wheels in the front and 9.5's in the back. The offset should be obvious, if yours does not than someone has switched them out.

The E36 M3's have spares. The reason the M roadsters and E46 M3s don't have spares is because the dual exhaust/muffler setup takes up too much room under the car to fit a spare. Since the E36 M3 has an exhaust that fits in the same location as the exhaust in the non-M cars, they still have a spare.

 

[knightpitt]

The M's, at least the roadsters do not come with spares. If you have a 98 M3 you should have a staggered setup, I believe 8inch wheels in the front and 9.5's in the back. The offset should be obvious, if yours does not than someone has switched them out.

Actually, they came with 7.5" fronts and 8.5" rears. So, you'll have to be sure that you actually still have the OEM BMW M3 wheels. The '95 M3 came with 7.5" on all 4 corners, so just because the wheels have the ///M on them doesn't necessarily mean that they're OEM.

For what it's worth, though, it's possible that the previous owner threw 235/40/17's on all four corners on the OEM rims. It's been known to happen. The reason can be either economic or performance oriented. AutoXers and the like sometimes toss 235's on the front and rear in order to balance out the handling a bit, allowing the car to rotate better and understeer less (more like the '95 M3). However, more often you'll find that people will buy aftermarket rims that are 8.5" all around so they can run 255's at every corner, which is really the better option. The other possibility (economic) is that he just wanted to be able to "rotate" (through remounting) the tires... which I guess is pretty doubtful. Or, it was just a mistake?

So, if you have the OEM size rims, I'd recommend the 225 front and 245 rear combo. 235 fronts are also fine, but are typically a bit of a squeeze to fit on a 7.5" rim. Some tire manufacturers don't rate their 235/40 tires for a 7.5" rim.

 

[jonaphn]

when i read the title, "Wheels and Oil"

i automatically thought to myself, "don't mix."

 

[BMRCRZ]

Thanks for the bit of humor mixed in there as well. knightpitt, are you saying you can actually fit 235's on a 245 rim? I didnt realize that was possible. As far as I can tell, the rims are the same size all around. I guess I will find out for sure when I go to replace the tires in a couple weeks.

Along those lines, I have read some tire posts, but I was hoping to get some more opinions. I am looking for a reasonable price (duh) with mostly dry performance, I really dont use the car in bad weather.

I know Kuhmo makes a decent cheap tire, but I wasnt sure if it would be worth it to upgrade to some Bridgestone Potenza's, Continentals or Goodyear Eagles or something. Thanks again for the responses

 

[Big Daddy]

Actually the stock wheels on my 98 M roadster are 7.5" fronts and 9.0" rears. I have run Kuhmos, Toyos and Michelin's. The Kuhmos are a good tire and perform well for daily use. They last forever, but are not as good a performance tire as the Toyos or the Michelin's. I will most likely go back to the Toyo Proxes as they are the mid-priced of the three, last longer and handle as well as the Michelin's.

 

[E30m42cab]

I have used Eagles and Toyos on my car, and I would have to say that the Toyo Proxes T-1S was a decent tire, but the Goodyear Eagle F1 GS D2's (its called the D3 now) are the best dry traction tire I've used... price for tires shouldn't really be a concern (within reason) They're the only things that actually touch the road and keep you on it... I'd hate to see an M3 (or any Bimmer) in the ditch becuase the tires were garbage. When I got my first bimmer, tires were the first thing I changed. Goodyear also tends to do alot of instant rebates, and in store rebates, so you can get some really good tires for a very good price if you keep an eye out.

 

[BMRCRZ]

Ok, so I finally figured out what was going on with the wheels. When I purchased the car, the guy told me he had put some semi used tires on because he was selling it, what I didnt realize was that he had put 225 all the way around. I didnt realize you could "stretch" out a tire to fit on a bigger rim. So basically, the tires he had on were too small, which probably contributed to the quick wear around the edges. So now that I have that figured out, I will be getting new tires next week that actually match spec. Thanks for all the advice and information.

 

[knightpitt]

I'm glad to hear that you got your wheel situation figured out...

For a tire selection, some people swear by the Kumho MX's for a good-priced, very good performing, dry tire. Personally, I use Hankook Ventus RS-2's (which are the almost-hot setup for STU AutoX). There's also Falken Azenis RT-615's, which are a great tire. Any of the above tires, however, should be used in the dry/summer only. If you're rolling around in Denver snow with any of those, you're not going anywhere.

If you plan to drive your car in the winter, you should very, very seriously consider a seperate set of rims with snow tires on them. All season tires are junk and absolutely do not do the trick for these cars in the snow.

 

[BMRCRZ]

Definitely agree on the winter wheels, luckily I still have a Jeep to keep me rolling around in the white stuff. Ive heard good things about the Hankook and Kuhmo's, even though they are a little "cheaper" Guess I will just have to decide what I am looking for. I never had to think about tires before, I guess thats what a sports car will get you doing.